.NET Information center: Project file must include the .NET Framework assembly 'WindowsBase, PresentationCore, PresentationFramework' in the reference list.

Sunday, August 22, 2010

Project file must include the .NET Framework assembly 'WindowsBase, PresentationCore, PresentationFramework' in the reference list.

I was adding a splash screen to my Silverlight project and ran into a sudden compile problem with the ASP.NET web site. The compile error was: Project file must include the .NET Framework assembly 'WindowsBase, PresentationCore, PresentationFramework' in the reference list. I verified that the loose Silverlight xaml file was set to just content, with no build action. However, I kept getting that error, even after a clean and rebuild. So I cracked open the project file, and saw that generator was still listed for the xaml files even though it was blank in the IDE:

<content include=

"ClientBin\Themes\GreenGardenTheme.xaml">

<subtype>Designer</subtype>

<generator>MSBuild:Compile</generator>

</content>

Changing that to read:

<content include=

"ClientBin\Themes\GreenGardenTheme.xaml"></content>

while correct, still didn’t fix the compile problem. So I poked around some more and discovered that a PNG file had somehow had its build action set to “Page” when I dragged it from the Silverlight project to the web project. “Page” is reserved for WPF apps. In the Silverlight app, it was set to “Resource”