After installing Silverlight 2 and Visual Studio Tools for SIlverligt 2, you may receive this errors if you have Blend 2.5 June preview installed.
Blend 2.5 version is not compatible with Visual Studio Tools for Silverlight, so solution for this is:
- Uninstall Blend 2.5 June preview.
- Install Blend 2 with SP1 (Silverlight).
In some cases you will have to uninstall Visual Studio Tools for Silverlight, Silverlight SDK and Blend 2.5 and install the same again but without Blend 2.5 (just Blend 2 with SP1).
But this solution worked for me.