Silverlight Developer runtime not installed Error
I started getting the error “Unable to start debugging. The Silverlight Developer Runtime is not installed. Please install a matching version.”. The error started poping after I installed Silverlight 4.0 tools. The resolution to this problem is to install Silverlight_Developer.exe. You can download the setup from http://go.microsoft.com/fwlink/?LinkID=188039 .
Thanks to the post http://forums.silverlight.net/forums/p/176999/421658.aspx