The “Microsoft.WebApplication.Build.Tasks.GetSilverlightItemsFromProperty” task could not be loaded from the assembly … Microsoft.WebApplication.Build.Tasks.dll. … The assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded. Confirm that the <UsingTaskk> declaration is correct, and that the assembly and all its dependencies are available.
So I am sure there is a way to tweak / edit the solution files and .csproj files to fix this. I had not gotten into much coding with the Silverlight side of this solution. I had been working on the Model and WCF stuff (targeting .NET 4.0) so I encountered this when I started on some ViewModel code.
Clearly this is because the WebApplication project created for the Silverlight 3 application is trying to build with the .NET 4.0 version of the MSBuild environment and Blend 3 wants the 3.5/2.0 version.
The simplest way to fix this is to create the Silverlight + Website project from Blend 3. Then Add the projects to your VS 2010 B2 solution. Then everything works.
