3 files changed, 19 insertions, 6 deletions

diff --git a/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs b/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
index 621be346..370364d1 100644
--- a/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
@@ -676,10 +676,16 @@ namespace WixToolset.Core.Burn
         {
             var symbols = this.Output.Sections.Single().Symbols.OfType<T>().ToList();
 
-            if (1 != symbols.Count)
+            if (0 == symbols.Count)
             {
                 throw new WixException(ErrorMessages.MissingBundleInformation(elementName));
             }
+            else if (1 < symbols.Count)
+            {
+                // We'll show the first two source line collisions. If there are more than that, the user
+                // may have to build multiple times to find them all. This should be very rare.
+                throw new WixException(BurnBackendErrors.MultipleSingletonSymbolsFound(symbols[0].SourceLineNumbers, elementName, symbols[1].SourceLineNumbers));
+            }
 
             return symbols[0];
         }
diff --git a/src/wix/WixToolset.Core.Burn/BurnBackendErrors.cs b/src/wix/WixToolset.Core.Burn/BurnBackendErrors.cs
index ee6fc0f8..c0e379ad 100644
--- a/src/wix/WixToolset.Core.Burn/BurnBackendErrors.cs
+++ b/src/wix/WixToolset.Core.Burn/BurnBackendErrors.cs
@@ -95,6 +95,11 @@ namespace WixToolset.Core.Burn
             return Message(sourceLineNumbers, Ids.InvalidBundleManifest, "Unable to read bundle executable '{0}'. Its manifest is invalid. {1}", bundleExecutable, reason);
         }
 
+        public static Message MultipleSingletonSymbolsFound(SourceLineNumber sourceLineNumbers, string friendlyName, SourceLineNumber collisionSourceLineNumbers)
+        {
+            return Message(sourceLineNumbers, Ids.MultipleSingletonSymbolsFound, "The Bundle requires a single {0}, but found another at: {1}", friendlyName, collisionSourceLineNumbers.ToString());
+        }
+
         private static Message Message(SourceLineNumber sourceLineNumber, Ids id, string format, params object[] args)
         {
             return new Message(sourceLineNumber, MessageLevel.Error, (int)id, format, args);
@@ -116,6 +121,7 @@ namespace WixToolset.Core.Burn
             FailedToUpdateBundleResources = 8011,
             InvalidBundleManifest = 8012,
             BundleMultipleProviders = 8013,
+            MultipleSingletonSymbolsFound = 8014,
         } // last available is 8499. 8500 is BurnBackendWarnings.
     }
 }
diff --git a/src/wix/WixToolset.Core/Compiler_Bundle.cs b/src/wix/WixToolset.Core/Compiler_Bundle.cs
index d0911fe9..b9cf8e82 100644
--- a/src/wix/WixToolset.Core/Compiler_Bundle.cs
+++ b/src/wix/WixToolset.Core/Compiler_Bundle.cs
@@ -439,6 +439,12 @@ namespace WixToolset.Core
                     });
                 }
 
+                this.Core.AddSymbol(new WixBundleContainerSymbol(sourceLineNumbers, Compiler.BurnUXContainerId)
+                {
+                    Name = "bundle-ux.cab",
+                    Type = ContainerType.Attached
+                });
+
                 this.Core.AddSymbol(new WixBundleContainerSymbol(sourceLineNumbers, Compiler.BurnDefaultAttachedContainerId)
                 {
                     Name = "bundle-attached.cab",
@@ -773,11 +779,6 @@ namespace WixToolset.Core
             if (!this.Core.EncounteredError)
             {
                 compilerPayload.CreatePayloadSymbol(ComplexReferenceParentType.Container, Compiler.BurnUXContainerId.Id);
-                this.Core.AddSymbol(new WixBundleContainerSymbol(sourceLineNumbers, Compiler.BurnUXContainerId)
-                {
-                    Name = "bundle-ux.cab",
-                    Type = ContainerType.Attached
-                });
 
                 this.Core.AddSymbol(new WixBootstrapperApplicationDllSymbol(sourceLineNumbers, compilerPayload.Id)
                 {