Ryan Alford explains how to cope with an error in Silverlight 4 when using Entity Framework 4.
Source: Eclipsed4utoo's Blog
Recently, I wanted to do a project in Silverlight 4 using EF4(Entity Framework 4). When I went to add the ADO.Net Entity Data Model class, I received this error message:
The project’s target framework does not contain Entity Framework runtime assemblies. Please review the target framework information in the project’s property page.
I checked my .Net framework version, and it was .Net 4.0. So I went searching on Google and found this thread on MSDN. It seems that there is a problem with VS2010/Productivity Power Tools when using EF4.