SharePoint 2010 Error Creating Sub-Sites: Unexpected error in Silverlight Application

If you see an “unexpected error in Silverlight application” error message when trying to create new sub-sites or other items on a SharePoint 2010 you need to check the web page security validation on your web application. Probably it is set to Off.


To change it:

  • Go to Central Administration.
  • Go to Application Management > Manage Web Applications.
  • Select the web application with the issue and click General Settings on the ribbon.
  • Change the Web Page Security Validation from Off to On.
  • Click OK to close the dialog.

Test the sub-site creation and the Silverlight should work just fine.


See you,