An unhandled exception occurred in the Silverlight Application

If you get an error "An unhandled exception occurred in the Silverlight Application in SharePoint 2010" when you try to create a document library, list, site or anything in SharePoint 2010.

I got this error in my environment when i created Picrure Library in Team site.
Genrally it could be that security validation has been disabled in Webpart Security Validation(Central Administration--> Web Application--> General Settings).

For detailed explanation please find this link