26 files changed, 620 insertions, 62 deletions

diff --git a/Bal.wixext.sln b/Bal.wixext.sln
index e84aab6f..867beef5 100644
--- a/Bal.wixext.sln
+++ b/Bal.wixext.sln
@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
-VisualStudioVersion = 15.0.28010.2016
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29503.13
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "bafunctions", "src\Samples\bafunctions\bafunctions.vcxproj", "{EB0A7D51-2133-4EE7-B6CA-87DBEAC67E02}"
 EndProject
@@ -15,6 +15,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixToolset.Bal.wixext", "sr
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "WixToolsetTest.MbaHost", "src\test\WixToolsetTest.MbaHost\WixToolsetTest.MbaHost.vcxproj", "{8C131CB9-7B1C-4B06-A328-E69CE9EDC763}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WixToolset.Mba.Host", "src\WixToolset.Mba.Host\WixToolset.Mba.Host.csproj", "{F2BA1935-70FA-4156-B161-FD03850B4FAA}"
+EndProject
 Global
         GlobalSection(SolutionConfigurationPlatforms) = preSolution
                 Debug|Any CPU = Debug|Any CPU
@@ -71,6 +73,14 @@ Global
                 {8C131CB9-7B1C-4B06-A328-E69CE9EDC763}.Release|Any CPU.Build.0 = Release|Win32
                 {8C131CB9-7B1C-4B06-A328-E69CE9EDC763}.Release|x86.ActiveCfg = Release|Win32
                 {8C131CB9-7B1C-4B06-A328-E69CE9EDC763}.Release|x86.Build.0 = Release|Win32
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Debug|x86.ActiveCfg = Debug|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Debug|x86.Build.0 = Debug|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Release|Any CPU.Build.0 = Release|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Release|x86.ActiveCfg = Release|Any CPU
+                {F2BA1935-70FA-4156-B161-FD03850B4FAA}.Release|x86.Build.0 = Release|Any CPU
         EndGlobalSection
         GlobalSection(SolutionProperties) = preSolution
                 HideSolutionNode = FALSE
diff --git a/appveyor.cmd b/appveyor.cmd
index c75d03ea..d3acaadb 100644
--- a/appveyor.cmd
+++ b/appveyor.cmd
@@ -8,6 +8,7 @@ msbuild -p:Configuration=Release -t:Restore
 msbuild -p:Configuration=Release
 
 msbuild -p:Configuration=Release -t:Pack src\wixext\WixToolset.Bal.wixext.csproj
+msbuild -p:Configuration=Release -t:Pack src\WixToolset.Mba.Host\WixToolset.Mba.Host.csproj
 
 @popd
 @endlocal
\ No newline at end of file
diff --git a/src/Samples/bafunctions/bafunctions.vcxproj b/src/Samples/bafunctions/bafunctions.vcxproj
index 5550ff60..22be1a35 100644
--- a/src/Samples/bafunctions/bafunctions.vcxproj
+++ b/src/Samples/bafunctions/bafunctions.vcxproj
@@ -2,8 +2,8 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props" Condition="Exists('..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" />
-  <Import Project="..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" />
+  <Import Project="..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props" Condition="Exists('..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" />
+  <Import Project="..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" />
   <Import Project="..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props" Condition="Exists('..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" />
 
   <ItemGroup Label="ProjectConfigurations">
@@ -57,8 +57,8 @@
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props'))" />
-    <Error Condition="!Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props'))" />
+    <Error Condition="!Exists('..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props'))" />
+    <Error Condition="!Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props'))" />
     <Error Condition="!Exists('..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props'))" />
     <Error Condition="!Exists('..\..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets'))" />
   </Target>
diff --git a/src/Samples/bafunctions/packages.config b/src/Samples/bafunctions/packages.config
index 7c46d4c5..f209d5fb 100644
--- a/src/Samples/bafunctions/packages.config
+++ b/src/Samples/bafunctions/packages.config
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Nerdbank.GitVersioning" version="2.1.65" targetFramework="native" developmentDependency="true" />
-  <package id="WixToolset.BootstrapperCore.Native" version="4.0.8" targetFramework="native" />
-  <package id="WixToolset.BalUtil" version="4.0.9" targetFramework="native" />
+  <package id="WixToolset.BootstrapperCore.Native" version="4.0.10" targetFramework="native" />
+  <package id="WixToolset.BalUtil" version="4.0.12" targetFramework="native" />
   <package id="WixToolset.DUtil" version="4.0.18" targetFramework="native" />
 </packages>
\ No newline at end of file
diff --git a/src/WixToolset.Mba.Host/BootstrapperApplicationFactory.cs b/src/WixToolset.Mba.Host/BootstrapperApplicationFactory.cs
new file mode 100644
index 00000000..9385d1d1
--- /dev/null
+++ b/src/WixToolset.Mba.Host/BootstrapperApplicationFactory.cs
@@ -0,0 +1,85 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Configuration;
+    using System.Reflection;
+    using System.Runtime.InteropServices;
+    using WixToolset.Mba.Core;
+
+    /// <summary>
+    /// Entry point for the MBA host to create and return the BA to the engine.
+    /// </summary>
+    [ClassInterface(ClassInterfaceType.None)]
+    public sealed class BootstrapperApplicationFactory : MarshalByRefObject, IBootstrapperApplicationFactory
+    {
+        /// <summary>
+        /// Creates a new instance of the <see cref="BootstrapperApplicationFactory"/> class.
+        /// </summary>
+        public BootstrapperApplicationFactory()
+        {
+        }
+
+        /// <summary>
+        /// Loads the bootstrapper application assembly and calls its IBootstrapperApplicationFactory.Create method.
+        /// </summary>
+        /// <param name="pArgs">Pointer to BOOTSTRAPPER_CREATE_ARGS struct.</param>
+        /// <param name="pResults">Pointer to BOOTSTRAPPER_CREATE_RESULTS struct.</param>
+        /// <exception cref="MissingAttributeException">The bootstrapper application assembly
+        /// does not define the <see cref="BootstrapperApplicationFactoryAttribute"/>.</exception>
+        public void Create(IntPtr pArgs, IntPtr pResults)
+        {
+            // Get the wix.boostrapper section group to get the name of the bootstrapper application assembly to host.
+            var section = ConfigurationManager.GetSection("wix.bootstrapper/host") as HostSection;
+            if (null == section)
+            {
+                throw new MissingAttributeException(); // TODO: throw a more specific exception than this.
+            }
+
+            // Load the BA's IBootstrapperApplicationFactory.
+            var baFactoryType = BootstrapperApplicationFactory.GetBAFactoryTypeFromAssembly(section.AssemblyName);
+            var baFactory = (IBootstrapperApplicationFactory)Activator.CreateInstance(baFactoryType);
+            if (null == baFactory)
+            {
+                throw new InvalidBootstrapperApplicationFactoryException();
+            }
+
+            baFactory.Create(pArgs, pResults);
+        }
+
+        /// <summary>
+        /// Locates the <see cref="BootstrapperApplicationFactoryAttribute"/> and returns the specified type.
+        /// </summary>
+        /// <param name="assemblyName">The assembly that defines the IBootstrapperApplicationFactory implementation.</param>
+        /// <returns>The bootstrapper application factory <see cref="Type"/>.</returns>
+        private static Type GetBAFactoryTypeFromAssembly(string assemblyName)
+        {
+            Type baFactoryType = null;
+
+            // Load the requested assembly.
+            Assembly asm = AppDomain.CurrentDomain.Load(assemblyName);
+
+            // If an assembly was loaded and is not the current assembly, check for the required attribute.
+            // This is done to avoid using the BootstrapperApplicationFactoryAttribute which we use at build time
+            // to specify the BootstrapperApplicationFactory assembly in the manifest.
+            if (!Assembly.GetExecutingAssembly().Equals(asm))
+            {
+                // There must be one and only one BootstrapperApplicationFactoryAttribute.
+                // The attribute prevents multiple declarations already.
+                var attrs = (BootstrapperApplicationFactoryAttribute[])asm.GetCustomAttributes(typeof(BootstrapperApplicationFactoryAttribute), false);
+                if (null != attrs)
+                {
+                    baFactoryType = attrs[0].BootstrapperApplicationFactoryType;
+                }
+            }
+
+            if (null == baFactoryType)
+            {
+                throw new MissingAttributeException();
+            }
+
+            return baFactoryType;
+        }
+    }
+}
diff --git a/src/WixToolset.Mba.Host/BootstrapperSectionGroup.cs b/src/WixToolset.Mba.Host/BootstrapperSectionGroup.cs
new file mode 100644
index 00000000..5cf1bc9c
--- /dev/null
+++ b/src/WixToolset.Mba.Host/BootstrapperSectionGroup.cs
@@ -0,0 +1,29 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Configuration;
+
+    /// <summary>
+    /// Handler for the wix.bootstrapper configuration section group.
+    /// </summary>
+    public class BootstrapperSectionGroup : ConfigurationSectionGroup
+    {
+        /// <summary>
+        /// Creates a new instance of the <see cref="BootstrapperSectionGroup"/> class.
+        /// </summary>
+        public BootstrapperSectionGroup()
+        {
+        }
+
+        /// <summary>
+        /// Gets the <see cref="HostSection"/> handler for the mba configuration section.
+        /// </summary>
+        [ConfigurationProperty("host")]
+        public HostSection Host
+        {
+            get { return (HostSection)base.Sections["host"]; }
+        }
+    }
+}
diff --git a/src/WixToolset.Mba.Host/Exceptions.cs b/src/WixToolset.Mba.Host/Exceptions.cs
new file mode 100644
index 00000000..c68951f0
--- /dev/null
+++ b/src/WixToolset.Mba.Host/Exceptions.cs
@@ -0,0 +1,145 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Runtime.Serialization;
+
+    /// <summary>
+    /// Base class for exception returned to the bootstrapper application host.
+    /// </summary>
+    [Serializable]
+    public abstract class BootstrapperException : Exception
+    {
+        /// <summary>
+        /// Creates an instance of the <see cref="BootstrapperException"/> base class with the given HRESULT.
+        /// </summary>
+        /// <param name="hr">The HRESULT for the exception that is used by the bootstrapper application host.</param>
+        public BootstrapperException(int hr)
+        {
+            this.HResult = hr;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BootstrapperException"/> class.
+        /// </summary>
+        /// <param name="message">Exception message.</param>
+        public BootstrapperException(string message)
+            : base(message)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BootstrapperException"/> class.
+        /// </summary>
+        /// <param name="message">Exception message</param>
+        /// <param name="innerException">Inner exception associated with this one</param>
+        public BootstrapperException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BootstrapperException"/> class.
+        /// </summary>
+        /// <param name="info">Serialization information for this exception</param>
+        /// <param name="context">Streaming context to serialize to</param>
+        protected BootstrapperException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+    }
+
+    /// <summary>
+    /// The bootstrapper application assembly loaded by the host does not contain exactly one instance of the
+    /// <see cref="Core.BootstrapperApplicationFactoryAttribute"/> class.
+    /// </summary>
+    /// <seealso cref="Core.BootstrapperApplicationFactoryAttribute"/>
+    [Serializable]
+    public class MissingAttributeException : BootstrapperException
+    {
+        /// <summary>
+        /// Creates a new instance of the <see cref="MissingAttributeException"/> class.
+        /// </summary>
+        public MissingAttributeException()
+            : base(NativeMethods.E_NOTFOUND)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MissingAttributeException"/> class.
+        /// </summary>
+        /// <param name="message">Exception message.</param>
+        public MissingAttributeException(string message)
+            : base(message)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MissingAttributeException"/> class.
+        /// </summary>
+        /// <param name="message">Exception message</param>
+        /// <param name="innerException">Inner exception associated with this one</param>
+        public MissingAttributeException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MissingAttributeException"/> class.
+        /// </summary>
+        /// <param name="info">Serialization information for this exception</param>
+        /// <param name="context">Streaming context to serialize to</param>
+        protected MissingAttributeException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+    }
+
+    /// <summary>
+    /// The bootstrapper application factory specified by the <see cref="Core.BootstrapperApplicationFactoryAttribute"/>
+    ///  does not extend the <see cref="Core.IBootstrapperApplicationFactory"/> base class.
+    /// </summary>
+    /// <seealso cref="Core.BaseBootstrapperApplicationFactory"/>
+    /// <seealso cref="Core.BootstrapperApplicationFactoryAttribute"/>
+    [Serializable]
+    public class InvalidBootstrapperApplicationFactoryException : BootstrapperException
+    {
+        /// <summary>
+        /// Creates a new instance of the <see cref="InvalidBootstrapperApplicationFactoryException"/> class.
+        /// </summary>
+        public InvalidBootstrapperApplicationFactoryException()
+            : base(NativeMethods.E_UNEXPECTED)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="InvalidBootstrapperApplicationFactoryException"/> class.
+        /// </summary>
+        /// <param name="message">Exception message.</param>
+        public InvalidBootstrapperApplicationFactoryException(string message)
+            : base(message)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="InvalidBootstrapperApplicationFactoryException"/> class.
+        /// </summary>
+        /// <param name="message">Exception message</param>
+        /// <param name="innerException">Inner exception associated with this one</param>
+        public InvalidBootstrapperApplicationFactoryException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="InvalidBootstrapperApplicationFactoryException"/> class.
+        /// </summary>
+        /// <param name="info">Serialization information for this exception</param>
+        /// <param name="context">Streaming context to serialize to</param>
+        protected InvalidBootstrapperApplicationFactoryException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+    }
+}
diff --git a/src/WixToolset.Mba.Host/HostSection.cs b/src/WixToolset.Mba.Host/HostSection.cs
new file mode 100644
index 00000000..632025c7
--- /dev/null
+++ b/src/WixToolset.Mba.Host/HostSection.cs
@@ -0,0 +1,47 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Configuration;
+
+    /// <summary>
+    /// Handler for the Host configuration section.
+    /// </summary>
+    public sealed class HostSection : ConfigurationSection
+    {
+        private static readonly ConfigurationProperty assemblyNameProperty = new ConfigurationProperty("assemblyName", typeof(string), null, ConfigurationPropertyOptions.IsRequired);
+        private static readonly ConfigurationProperty supportedFrameworksProperty = new ConfigurationProperty("", typeof(SupportedFrameworkElementCollection), null, ConfigurationPropertyOptions.IsDefaultCollection);
+
+        /// <summary>
+        /// Creates a new instance of the <see cref="HostSection"/> class.
+        /// </summary>
+        public HostSection()
+        {
+        }
+
+        /// <summary>
+        /// Gets the name of the assembly that contians the <see cref="Core.IBootstrapperApplicationFactory"/> child class.
+        /// </summary>
+        /// <remarks>
+        /// The assembly specified by this name must contain the <see cref="Core.BootstrapperApplicationFactoryAttribute"/> to identify
+        /// the type of the <see cref="Core.IBootstrapperApplicationFactory"/> child class.
+        /// </remarks>
+        [ConfigurationProperty("assemblyName", IsRequired = true)]
+        public string AssemblyName
+        {
+            get { return (string)base[assemblyNameProperty]; }
+            set { base[assemblyNameProperty] = value; }
+        }
+
+        /// <summary>
+        /// Gets the <see cref="SupportedFrameworkElementCollection"/> of supported frameworks for the host configuration.
+        /// </summary>
+        [ConfigurationProperty("", IsDefaultCollection = true)]
+        [ConfigurationCollection(typeof(SupportedFrameworkElement))]
+        public SupportedFrameworkElementCollection SupportedFrameworks
+        {
+            get { return (SupportedFrameworkElementCollection)base[supportedFrameworksProperty]; }
+        }
+    }
+}
diff --git a/src/WixToolset.Mba.Host/NativeMethods.cs b/src/WixToolset.Mba.Host/NativeMethods.cs
new file mode 100644
index 00000000..b9fc85a0
--- /dev/null
+++ b/src/WixToolset.Mba.Host/NativeMethods.cs
@@ -0,0 +1,18 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Runtime.InteropServices;
+
+    /// <summary>
+    /// Contains native constants, functions, and structures for this assembly.
+    /// </summary>
+    internal static class NativeMethods
+    {
+        #region Error Constants
+        internal const int E_NOTFOUND = unchecked((int)0x80070490);
+        internal const int E_UNEXPECTED = unchecked((int)0x8000ffff);
+        #endregion
+    }
+}
diff --git a/src/WixToolset.Mba.Host/Properties/AssemblyInfo.cs b/src/WixToolset.Mba.Host/Properties/AssemblyInfo.cs
new file mode 100644
index 00000000..8cee0ae9
--- /dev/null
+++ b/src/WixToolset.Mba.Host/Properties/AssemblyInfo.cs
@@ -0,0 +1,17 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+using System;
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+[assembly: AssemblyTitle("Managed Bootstrapper Application Host (WiX)")]
+[assembly: AssemblyDescription("Managed Bootstrapper Application Host")]
+[assembly: AssemblyProduct("WiX Toolset")]
+[assembly: AssemblyCompany("WiX Toolset Team")]
+[assembly: AssemblyCopyright("Copyright (c) .NET Foundation and contributors. All rights reserved.")]
+
+// Types should not be visible to COM by default.
+[assembly: ComVisible(false)]
+[assembly: Guid("6f4e0cc9-8ad4-4b5a-a669-3aafff67a76f")]
+
+[assembly: CLSCompliantAttribute(true)]
diff --git a/src/WixToolset.Mba.Host/SupportedFrameworkElement.cs b/src/WixToolset.Mba.Host/SupportedFrameworkElement.cs
new file mode 100644
index 00000000..fe7fd2eb
--- /dev/null
+++ b/src/WixToolset.Mba.Host/SupportedFrameworkElement.cs
@@ -0,0 +1,47 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Configuration;
+
+    /// <summary>
+    /// Handler for the supportedFramework configuration section.
+    /// </summary>
+    public sealed class SupportedFrameworkElement : ConfigurationElement
+    {
+        private static readonly ConfigurationProperty versionProperty = new ConfigurationProperty("version", typeof(string), null, ConfigurationPropertyOptions.IsRequired);
+        private static readonly ConfigurationProperty runtimeVersionProperty = new ConfigurationProperty("runtimeVersion", typeof(string));
+
+        /// <summary>
+        /// Creates a new instance of the <see cref="SupportedFrameworkElement"/> class.
+        /// </summary>
+        public SupportedFrameworkElement()
+        {
+        }
+
+        /// <summary>
+        /// Gets the version of the supported framework.
+        /// </summary>
+        /// <remarks>
+        /// The assembly specified by this name must contain a value matching the NETFX version registry key under
+        /// "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP".
+        /// </remarks>
+        [ConfigurationProperty("version", IsRequired = true)]
+        public string Version
+        {
+            get { return (string)base[versionProperty]; }
+            set { base[versionProperty] = value; }
+        }
+
+        /// <summary>
+        /// Gets the runtime version required by this supported framework.
+        /// </summary>
+        [ConfigurationProperty("runtimeVersion", IsRequired = false)]
+        public string RuntimeVersion
+        {
+            get { return (string)base[runtimeVersionProperty]; }
+            set { base[runtimeVersionProperty] = value; }
+        }
+    }
+}
diff --git a/src/WixToolset.Mba.Host/SupportedFrameworkElementCollection.cs b/src/WixToolset.Mba.Host/SupportedFrameworkElementCollection.cs
new file mode 100644
index 00000000..12c7cf3e
--- /dev/null
+++ b/src/WixToolset.Mba.Host/SupportedFrameworkElementCollection.cs
@@ -0,0 +1,36 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Host
+{
+    using System;
+    using System.Configuration;
+    using System.Diagnostics.CodeAnalysis;
+
+    /// <summary>
+    /// Handler for the supportedFramework collection.
+    /// </summary>
+    [SuppressMessage("Microsoft.Design", "CA1010:CollectionsShouldImplementGenericInterface")]
+    [ConfigurationCollection(typeof(SupportedFrameworkElement), AddItemName = "supportedFramework", CollectionType = ConfigurationElementCollectionType.BasicMap)]
+    public sealed class SupportedFrameworkElementCollection : ConfigurationElementCollection
+    {
+        public override ConfigurationElementCollectionType CollectionType
+        {
+            get { return ConfigurationElementCollectionType.BasicMap; }
+        }
+
+        protected override string ElementName
+        {
+            get { return "supportedFramework"; }
+        }
+
+        protected override ConfigurationElement CreateNewElement()
+        {
+            return new SupportedFrameworkElement();
+        }
+
+        protected override object GetElementKey(ConfigurationElement element)
+        {
+            return (element as SupportedFrameworkElement).Version;
+        }
+    }
+}
diff --git a/src/WixToolset.Mba.Host/WixToolset.Mba.Host.config b/src/WixToolset.Mba.Host/WixToolset.Mba.Host.config
new file mode 100644
index 00000000..a19b66f1
--- /dev/null
+++ b/src/WixToolset.Mba.Host/WixToolset.Mba.Host.config
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
+
+
+<configuration>
+    <configSections>
+        <sectionGroup name="wix.bootstrapper" type="WixToolset.Mba.Host.BootstrapperSectionGroup, WixToolset.Mba.Host">
+            <section name="host" type="WixToolset.Mba.Host.HostSection, WixToolset.Mba.Host" />
+        </sectionGroup>
+    </configSections>
+    <startup useLegacyV2RuntimeActivationPolicy="true">
+        <supportedRuntime version="v4.0" />
+        <supportedRuntime version="v2.0.50727" />
+    </startup>
+    <wix.bootstrapper>
+        <!-- Example only. Use only if the startup/supportedRuntime above cannot discern supported frameworks. -->
+        <!--
+        <supportedFramework version="v4\Client" />
+        <supportedFramework version="v3.5" />
+        <supportedFramework version="v3.0" />
+        -->
+
+        <!-- Example only. Replace the host/@assemblyName attribute with assembly that implements IBootstrapperApplicationFactory. -->
+        <host assemblyName="AssemblyWithClassThatInheritsFromBootstrapperApplicationFactory" />
+    </wix.bootstrapper>
+</configuration>
diff --git a/src/WixToolset.Mba.Host/WixToolset.Mba.Host.csproj b/src/WixToolset.Mba.Host/WixToolset.Mba.Host.csproj
new file mode 100644
index 00000000..ccdd67cf
--- /dev/null
+++ b/src/WixToolset.Mba.Host/WixToolset.Mba.Host.csproj
@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
+
+
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ProjectGuid>{F2BA1935-70FA-4156-B161-FD03850B4FAA}</ProjectGuid>
+    <AssemblyName>WixToolset.Mba.Host</AssemblyName>
+    <OutputType>Library</OutputType>
+    <RootNamespace>WixToolset.Mba.Host</RootNamespace>
+    <NoWarn>0693;1591</NoWarn>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <Description>Managed Bootstrapper Application entry point</Description>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+    <DebugSymbols>true</DebugSymbols>
+    <Optimize>false</Optimize>
+    <DefineConstants>$(DefineConstants);DEBUG;TRACE</DefineConstants>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+    <DebugSymbols>true</DebugSymbols>
+    <Optimize>true</Optimize>
+    <DefineConstants>$(DefineConstants);TRACE</DefineConstants>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="BootstrapperApplicationFactory.cs" />
+    <Compile Include="BootstrapperSectionGroup.cs" />
+    <Compile Include="Exceptions.cs" />
+    <Compile Include="HostSection.cs" />
+    <Compile Include="NativeMethods.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="SupportedFrameworkElementCollection.cs" />
+    <Compile Include="SupportedFrameworkElement.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="WixToolset.Mba.Host.config" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Configuration" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+    <Reference Include="WixToolset.Mba.Core">
+      <HintPath>..\..\packages\WixToolset.Mba.Core.4.0.12\lib\net20\WixToolset.Mba.Core.dll</HintPath>
+    </Reference>
+  </ItemGroup>
+  <ItemGroup>
+    <HeaderPath Include="$(BaseOutputPath)obj\$(AssemblyName).h">
+      <Visible>False</Visible>
+    </HeaderPath>
+  </ItemGroup>
+
+  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
+
+  <Target Name="GenerateIdentityHeader" AfterTargets="Build" Inputs="$(TargetPath)" Outputs="@(HeaderPath)">
+    <GetAssemblyIdentity AssemblyFiles="$(TargetPath)">
+      <Output TaskParameter="Assemblies" ItemName="AssemblyIdentity" />
+    </GetAssemblyIdentity>
+    <ItemGroup>
+      <Line Include="#define MBA_ASSEMBLY_FULL_NAME L&quot;%(AssemblyIdentity.Identity)&quot;" />
+      <Line Include="#define MBA_CONFIG_FILE_NAME L&quot;$(AssemblyName).config&quot;" />
+      <Line Include="#define MBA_ENTRY_TYPE L&quot;$(RootNamespace).BootstrapperApplicationFactory&quot;" />
+    </ItemGroup>
+    <Message Importance="normal" Text="Generating identity definitions into @(HeaderPath->'%(FullPath)')" />
+    <WriteLinesToFile File="@(HeaderPath)" Lines="@(Line)" Overwrite="True" />
+    <ItemGroup>
+      <FileWrites Include="@(HeaderPath)" />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="Pack" DependsOnTargets="GetBuildVersion">
+    <Exec Command='nuget pack $(AssemblyName).nuspec -OutputDirectory "$(BaseOutputPath)$(Configuration)" -Properties Configuration=$(Configuration);Id=$(AssemblyName);Version="$(BuildVersionSimple)";Authors="$(Authors)";Copyright="$(Copyright)";Description="$(Description)";Title="$(Title)"' />
+  </Target>
+
+  <Import Project="..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets" Condition="Exists('..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets'))" />
+  </Target>
+
+  <PropertyGroup Condition=" '$(CreateDocumentation)'!='false' ">
+    <DocumentationFile>$(OutputPath)\$(AssemblyName).xml</DocumentationFile>
+  </PropertyGroup>
+</Project>
\ No newline at end of file
diff --git a/src/WixToolset.Mba.Host/WixToolset.Mba.Host.nuspec b/src/WixToolset.Mba.Host/WixToolset.Mba.Host.nuspec
new file mode 100644
index 00000000..101a6671
--- /dev/null
+++ b/src/WixToolset.Mba.Host/WixToolset.Mba.Host.nuspec
@@ -0,0 +1,20 @@
+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>$id$</id>
+    <version>$version$</version>
+    <authors>WiX Toolset Team</authors>
+    <owners>WiX Toolset Team</owners>
+    <!-- <license type="expression">MS-RL</license> -->
+    <licenseUrl>https://licenses.nuget.org/MS-RL</licenseUrl>
+    <projectUrl>https://github.com/wixtoolset/Bal.wixext</projectUrl>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <description>$description$</description>
+    <copyright>$copyright$</copyright>
+  </metadata>
+
+  <files>
+    <file src="$id$.config" target="samples" />
+    <file src="..\..\build\$configuration$\$id$.dll" target="lib\net20" />
+  </files>
+</package>
diff --git a/src/WixToolset.Mba.Host/packages.config b/src/WixToolset.Mba.Host/packages.config
new file mode 100644
index 00000000..eee20511
--- /dev/null
+++ b/src/WixToolset.Mba.Host/packages.config
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Nerdbank.GitVersioning" version="2.1.65" targetFramework="net20" developmentDependency="true" />
+  <package id="WixToolset.Mba.Core" version="4.0.12" targetFramework="net20" />
+</packages>
\ No newline at end of file
diff --git a/src/mbahost/mbahost.cpp b/src/mbahost/mbahost.cpp
index 444a95a8..7916ec9a 100644
--- a/src/mbahost/mbahost.cpp
+++ b/src/mbahost/mbahost.cpp
@@ -1,8 +1,7 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
 #include "precomp.h"
-#include <WixToolset.Mba.Core.h> // includes the generated assembly name macros.
-#include "BalBaseBootstrapperApplicationProc.h"
+#include <WixToolset.Mba.Host.h> // includes the generated assembly name macros.
 
 static const DWORD NET452_RELEASE = 379893;
 
@@ -50,7 +49,6 @@ static HRESULT GetCLRHost(
     );
 static HRESULT CreateManagedBootstrapperApplication(
     __in _AppDomain* pAppDomain,
-    __in IBootstrapperEngine* pEngine,
     __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
     __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
     );
@@ -109,7 +107,7 @@ extern "C" HRESULT WINAPI BootstrapperApplicationCreate(
     {
         BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Loading managed bootstrapper application.");
 
-        hr = CreateManagedBootstrapperApplication(vpAppDomain, pEngine, pArgs, pResults);
+        hr = CreateManagedBootstrapperApplication(vpAppDomain, pArgs, pResults);
         BalExitOnFailure(hr, "Failed to create the managed bootstrapper application.");
     }
     else // fallback to the prerequisite BA.
@@ -185,7 +183,7 @@ static HRESULT GetAppDomain(
     hr = GetAppBase(&sczAppBase);
     ExitOnFailure(hr, "Failed to get the host base path.");
 
-    hr = PathConcat(sczAppBase, L"WixToolset.Mba.Core.config", &sczConfigPath);
+    hr = PathConcat(sczAppBase, MBA_CONFIG_FILE_NAME, &sczConfigPath);
     ExitOnFailure(hr, "Failed to get the full path to the application configuration file.");
 
     // Check that the supported framework is installed.
@@ -514,27 +512,20 @@ LExit:
 // Creates the bootstrapper app and returns it for the engine.
 static HRESULT CreateManagedBootstrapperApplication(
     __in _AppDomain* pAppDomain,
-    __in IBootstrapperEngine* pEngine,
     __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
     __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
     )
 {
     HRESULT hr = S_OK;
     IBootstrapperApplicationFactory* pAppFactory = NULL;
-    IBootstrapperApplication* pApp = NULL;
 
     hr = CreateManagedBootstrapperApplicationFactory(pAppDomain, &pAppFactory);
     ExitOnFailure(hr, "Failed to create the factory to create the bootstrapper application.");
 
-    hr = pAppFactory->Create(pEngine, pArgs->pCommand, &pApp);
+    hr = pAppFactory->Create(pArgs, pResults);
     ExitOnFailure(hr, "Failed to create the bootstrapper application.");
 
-    pResults->pfnBootstrapperApplicationProc = BalBaseBootstrapperApplicationProc;
-    pResults->pvBootstrapperApplicationProcContext = pApp;
-    pApp = NULL;
-
 LExit:
-    ReleaseNullObject(pApp);
     ReleaseNullObject(pAppFactory);
 
     return hr;
@@ -557,7 +548,7 @@ static HRESULT CreateManagedBootstrapperApplicationFactory(
     bstrAssemblyName = ::SysAllocString(MBA_ASSEMBLY_FULL_NAME);
     ExitOnNull(bstrAssemblyName, hr, E_OUTOFMEMORY, "Failed to allocate the full assembly name for the bootstrapper application factory.");
 
-    bstrTypeName = ::SysAllocString(L"WixToolset.Mba.Core.BootstrapperApplicationFactory");
+    bstrTypeName = ::SysAllocString(MBA_ENTRY_TYPE);
     ExitOnNull(bstrTypeName, hr, E_OUTOFMEMORY, "Failed to allocate the full type name for the BA factory.");
 
     hr = pAppDomain->CreateInstance(bstrAssemblyName, bstrTypeName, &pObj);
diff --git a/src/mbahost/mbahost.vcxproj b/src/mbahost/mbahost.vcxproj
index c7a0b69f..30bffb54 100644
--- a/src/mbahost/mbahost.vcxproj
+++ b/src/mbahost/mbahost.vcxproj
@@ -2,8 +2,8 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props" Condition="Exists('..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" />
-  <Import Project="..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" />
+  <Import Project="..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props" Condition="Exists('..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" />
+  <Import Project="..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" />
   <Import Project="..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props" Condition="Exists('..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" />
 
   <ItemGroup Label="ProjectConfigurations">
@@ -52,13 +52,14 @@
 
   <ItemDefinitionGroup>
     <ClCompile>
-      <AdditionalIncludeDirectories>..\..\packages\WixToolset.Mba.Core.4.0.9\build\native\include\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(BaseOutputPath)obj;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
   </ItemDefinitionGroup>
 
   <ItemGroup>
-    <MbaHostDependency Include="..\..\packages\WixToolset.BootstrapperCore.4.0.8\lib\net20\WixToolset.BootstrapperCore.dll" />
-    <MbaHostDependency Include="..\..\packages\WixToolset.Mba.Core.4.0.9\lib\net20\WixToolset.Mba.Core.dll" />
+    <ProjectReference Include="..\WixToolset.Mba.Host\WixToolset.Mba.Host.csproj">
+      <Project>{f2ba1935-70fa-4156-b161-fd03850b4faa}</Project>
+    </ProjectReference>
   </ItemGroup>
 
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
@@ -67,13 +68,9 @@
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props'))" />
-    <Error Condition="!Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props'))" />
+    <Error Condition="!Exists('..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props'))" />
+    <Error Condition="!Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props'))" />
     <Error Condition="!Exists('..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props'))" />
     <Error Condition="!Exists('..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets'))" />
   </Target>
-
-  <Target Name="CopyMbaHostDependencies" AfterTargets="Build">
-    <Copy DestinationFolder="$(OutputPath)" SourceFiles="@(MbaHostDependency)" SkipUnchangedFiles="true" />
-  </Target>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/src/mbahost/packages.config b/src/mbahost/packages.config
index c616685e..f209d5fb 100644
--- a/src/mbahost/packages.config
+++ b/src/mbahost/packages.config
@@ -1,9 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Nerdbank.GitVersioning" version="2.1.65" targetFramework="native" developmentDependency="true" />
-  <package id="WixToolset.BootstrapperCore" version="4.0.8" targetFramework="native" />
-  <package id="WixToolset.BootstrapperCore.Native" version="4.0.8" targetFramework="native" />
-  <package id="WixToolset.BalUtil" version="4.0.9" targetFramework="native" />
+  <package id="WixToolset.BootstrapperCore.Native" version="4.0.10" targetFramework="native" />
+  <package id="WixToolset.BalUtil" version="4.0.12" targetFramework="native" />
   <package id="WixToolset.DUtil" version="4.0.18" targetFramework="native" />
-  <package id="WixToolset.Mba.Core" version="4.0.9" targetFramework="native" />
 </packages>
\ No newline at end of file
diff --git a/src/test/WixToolsetTest.MbaHost/TestManagedBootstrapperApplication.h b/src/test/WixToolsetTest.MbaHost/TestManagedBootstrapperApplication.h
index 8142b26c..d2b53718 100644
--- a/src/test/WixToolsetTest.MbaHost/TestManagedBootstrapperApplication.h
+++ b/src/test/WixToolsetTest.MbaHost/TestManagedBootstrapperApplication.h
@@ -8,7 +8,6 @@ namespace MbaHost
 namespace Native
 {
     using namespace System;
-    using namespace WixToolset::BootstrapperCore;
     using namespace WixToolset::Mba::Core;
 
     public ref class TestManagedBootstrapperApplication : BootstrapperApplication
diff --git a/src/test/WixToolsetTest.MbaHost/WixToolset.Mba.Core.config b/src/test/WixToolsetTest.MbaHost/WixToolset.Mba.Host.config
index 18bfbfc2..53a3d29e 100644
--- a/src/test/WixToolsetTest.MbaHost/WixToolset.Mba.Core.config
+++ b/src/test/WixToolsetTest.MbaHost/WixToolset.Mba.Host.config
@@ -4,8 +4,8 @@
 
 <configuration>
     <configSections>
-        <sectionGroup name="wix.bootstrapper" type="WixToolset.Mba.Core.BootstrapperSectionGroup, WixToolset.Mba.Core">
-            <section name="host" type="WixToolset.Mba.Core.HostSection, WixToolset.Mba.Core" />
+        <sectionGroup name="wix.bootstrapper" type="WixToolset.Mba.Host.BootstrapperSectionGroup, WixToolset.Mba.Host">
+            <section name="host" type="WixToolset.Mba.Host.HostSection, WixToolset.Mba.Host" />
         </sectionGroup>
     </configSections>
     <startup useLegacyV2RuntimeActivationPolicy="true">
diff --git a/src/test/WixToolsetTest.MbaHost/WixToolsetTest.MbaHost.vcxproj b/src/test/WixToolsetTest.MbaHost/WixToolsetTest.MbaHost.vcxproj
index b82f9194..d8143880 100644
--- a/src/test/WixToolsetTest.MbaHost/WixToolsetTest.MbaHost.vcxproj
+++ b/src/test/WixToolsetTest.MbaHost/WixToolsetTest.MbaHost.vcxproj
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props" Condition="Exists('..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" />
-  <Import Project="..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" />
+  <Import Project="..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props" Condition="Exists('..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" />
+  <Import Project="..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" />
   <Import Project="..\..\..\packages\xunit.core.2.4.0\build\xunit.core.props" Condition="Exists('..\..\..\packages\xunit.core.2.4.0\build\xunit.core.props')" />
   <Import Project="..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props" Condition="Exists('..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" />
   <ItemGroup Label="ProjectConfigurations">
@@ -48,7 +48,10 @@
   <ItemGroup>
     <None Include="packages.config" />
     <Content Include="BootstrapperApplicationData.xml" CopyToOutputDirectory="PreserveNewest" />
-    <Content Include="WixToolset.Mba.Core.config" CopyToOutputDirectory="PreserveNewest" />
+    <Content Include="WixToolset.Mba.Host.config" CopyToOutputDirectory="PreserveNewest" />
+    <Content Include="..\..\..\packages\WixToolset.Mba.Core.4.0.12\build\native\x86\mbanative.dll" Condition="Exists('..\..\..\packages\WixToolset.Mba.Core.4.0.12\build\native\x86\mbanative.dll')" CopyToOutputDirectory="PreserveNewest">
+      <Visible>False</Visible>
+    </Content>
   </ItemGroup>
   <ItemGroup>
     <Reference Include="System" />
@@ -65,11 +68,8 @@
     <Reference Include="xunit.execution.desktop">
       <HintPath>..\..\..\packages\xunit.extensibility.execution.2.4.0\lib\net452\xunit.execution.desktop.dll</HintPath>
     </Reference>
-    <Reference Include="WixToolset.BootstrapperCore">
-      <HintPath>..\..\..\packages\WixToolset.BootstrapperCore.4.0.8\lib\net20\WixToolset.BootstrapperCore.dll</HintPath>
-    </Reference>
     <Reference Include="WixToolset.Mba.Core">
-      <HintPath>..\..\..\packages\WixToolset.Mba.Core.4.0.9\lib\net20\WixToolset.Mba.Core.dll</HintPath>
+      <HintPath>..\..\..\packages\WixToolset.Mba.Core.4.0.12\lib\net20\WixToolset.Mba.Core.dll</HintPath>
     </Reference>
   </ItemGroup>
   <ItemGroup>
@@ -85,8 +85,8 @@
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props'))" />
-    <Error Condition="!Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props'))" />
+    <Error Condition="!Exists('..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props'))" />
+    <Error Condition="!Exists('..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props'))" />
     <Error Condition="!Exists('..\..\..\packages\xunit.core.2.4.0\build\xunit.core.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\xunit.core.2.4.0\build\xunit.core.props'))" />
     <Error Condition="!Exists('..\..\..\packages\xunit.core.2.4.0\build\xunit.core.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\xunit.core.2.4.0\build\xunit.core.targets'))" />
     <Error Condition="!Exists('..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props'))" />
diff --git a/src/test/WixToolsetTest.MbaHost/packages.config b/src/test/WixToolsetTest.MbaHost/packages.config
index c0615f19..4e9838f6 100644
--- a/src/test/WixToolsetTest.MbaHost/packages.config
+++ b/src/test/WixToolsetTest.MbaHost/packages.config
@@ -8,9 +8,8 @@
   <package id="xunit.extensibility.core" version="2.4.0" targetFramework="net461" />
   <package id="xunit.extensibility.execution" version="2.4.0" targetFramework="net461" />
   <package id="xunit.runner.visualstudio" version="2.4.0" targetFramework="net461" />
-  <package id="WixToolset.BalUtil" version="4.0.9" targetFramework="native" />
-  <package id="WixToolset.BootstrapperCore" version="4.0.8" targetFramework="net461" />
-  <package id="WixToolset.BootstrapperCore.Native" version="4.0.8" targetFramework="native" />
+  <package id="WixToolset.BalUtil" version="4.0.12" targetFramework="native" />
+  <package id="WixToolset.BootstrapperCore.Native" version="4.0.10" targetFramework="native" />
   <package id="WixToolset.DUtil" version="4.0.18" targetFramework="native" />
-  <package id="WixToolset.Mba.Core" version="4.0.9" targetFramework="net461" />
+  <package id="WixToolset.Mba.Core" version="4.0.12" targetFramework="net461" />
 </packages>
\ No newline at end of file
diff --git a/src/wixlib/Mba.wxs b/src/wixlib/Mba.wxs
index 05b57100..a99b41d8 100644
--- a/src/wixlib/Mba.wxs
+++ b/src/wixlib/Mba.wxs
@@ -40,8 +40,7 @@
 
     <Fragment>
         <PayloadGroup Id='Mba'>
-            <Payload Compressed='yes' SourceFile='WixToolset.BootstrapperCore.dll' />
-            <Payload Compressed='yes' SourceFile='WixToolset.Mba.Core.dll' />
+            <Payload Compressed='yes' SourceFile='WixToolset.Mba.Host.dll' />
             <Payload Compressed='yes' SourceFile='wixstdba.dll' Name='mbapreq.dll' />
         </PayloadGroup>
     </Fragment>
diff --git a/src/wixstdba/packages.config b/src/wixstdba/packages.config
index 7c46d4c5..f209d5fb 100644
--- a/src/wixstdba/packages.config
+++ b/src/wixstdba/packages.config
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Nerdbank.GitVersioning" version="2.1.65" targetFramework="native" developmentDependency="true" />
-  <package id="WixToolset.BootstrapperCore.Native" version="4.0.8" targetFramework="native" />
-  <package id="WixToolset.BalUtil" version="4.0.9" targetFramework="native" />
+  <package id="WixToolset.BootstrapperCore.Native" version="4.0.10" targetFramework="native" />
+  <package id="WixToolset.BalUtil" version="4.0.12" targetFramework="native" />
   <package id="WixToolset.DUtil" version="4.0.18" targetFramework="native" />
 </packages>
\ No newline at end of file
diff --git a/src/wixstdba/wixstdba.vcxproj b/src/wixstdba/wixstdba.vcxproj
index c3d3ede7..b0f767fb 100644
--- a/src/wixstdba/wixstdba.vcxproj
+++ b/src/wixstdba/wixstdba.vcxproj
@@ -2,8 +2,8 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props" Condition="Exists('..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" />
-  <Import Project="..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" />
+  <Import Project="..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props" Condition="Exists('..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" />
+  <Import Project="..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props" Condition="Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" />
   <Import Project="..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props" Condition="Exists('..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" />
 
   <ItemGroup Label="ProjectConfigurations">
@@ -107,8 +107,8 @@ rc.exe -fo "$(OutDir)wixstdba.res" "$(IntDir)wixstdba.messages.rc"</Command>
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BalUtil.4.0.9\build\WixToolset.BalUtil.props'))" />
-    <Error Condition="!Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BootstrapperCore.Native.4.0.8\build\WixToolset.BootstrapperCore.Native.props'))" />
+    <Error Condition="!Exists('..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BalUtil.4.0.12\build\WixToolset.BalUtil.props'))" />
+    <Error Condition="!Exists('..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.BootstrapperCore.Native.4.0.10\build\WixToolset.BootstrapperCore.Native.props'))" />
     <Error Condition="!Exists('..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\WixToolset.DUtil.4.0.18\build\WixToolset.DUtil.props'))" />
     <Error Condition="!Exists('..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\Nerdbank.GitVersioning.2.1.65\build\Nerdbank.GitVersioning.targets'))" />
   </Target>