I have just downloaded and started to play with Silverlight 4 in Visual Studio 2010 Beta 2.
In attempt to create a Silverlight Business Application, i got this error message:
Error 1 The type or namespace name ‘UserRegistrationContext’ could not be found (are you missing a using directive or an assembly reference?) h:\Personal\Visual Studio 2010\Projects\BusinessApplication1\BusinessApplication1\Views\Login\RegistrationForm.xaml.cs 22 13 BusinessApplication1
I also got this warning:
Warning 1 Assembly ‘h:\Personal\Visual Studio 2010\Projects\BusinessApplication1\BusinessApplication1.Web\bin\BusinessApplication1.Web.dll’ could not be loaded and will be ignored.
Could not load file or assembly ‘file:///h:\Personal\Visual Studio 2010\Projects\BusinessApplication1\BusinessApplication1.Web\bin\BusinessApplication1.Web.dll’ or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515) BusinessApplication1
This was not good, and searching it using Bing didn’t get any useful information.
As it turns out, the reason was that I have created the project on a network drive. Creating a Business Application on the local driver worked. It seems that the reason was that the project on the network drive was not trusted, and therefore the reference to the Web project failed.