Some of you might have come across the error “Unexpected error in Silverlight Application” while trying to create new sites or lists in SharePoint 2010 especially with newly created web applications. Here is a simple fix.
- Navigate to Central Admin > Application Management > Manage Web Applications.
- Select the web application having the issue and click General Settings on the ribbon.
- Change Web Page Security Validation from Off to On. Click OK to close the window.