Uses WixInternalUIBootstrapperApplication as the Bootstrapper Application for a Bundle. WixInternalUIBootstrapperApplication has no UI itself, it relies on the splash screen, prereq BA, and MSI UI. wixiuiba is not a typical BA because it has very specific requirements for the packages in the chain. There can only be one non-permanent package in the chain, and it needs to be the last package. The only exception is that multiple non-permanent packages can be specified with bal:PrimaryPackageType with a specific architecture. Each primary package must be an MsiPackage that contains UI for install and maintenance. If there are permanent packages, then they are always installed through the same prereq BA that is used for the managed BA hosts before executing the primary package. Due to Windows limitations, a splash screen should be provided so that the elevation prompt and MSI UI is automatically given focus. Extensibility point in the WiX XML Schema. Schema extensions can register additional elements at this point in the schema. Source file of the logo graphic. Source file of the theme XML. Source file of the theme localization .wxl file. The built-in theme to use. Extensibility point in the WiX XML Schema. Schema extensions can register additional attributes at this point in the schema.