I have installed Visual Studio 2010 Beta 2 professional. I have also installed the Silverlight 4 SDK and the Silverlight 4 Toolkit. When I try to migrate an existing an RIA Services project that ran fine on Visual Studio 2008 I get the error "Could not load file or assembly 'System.Core, Version 2.0.5.0'... for each xaml file in the application.
When I create a new Silverlight 4 application using the Silverlight Business Application Template or try build or run a Silverlight 4 RIA Services sample application I also get the same error message for each xaml file in the application.
I would appreciate any suggestions on what I can do to get this problem corrected.