I recently come across the above error and never documented my solution. Then the next time i came across it i spent just along trying to fix it. The first thing i did was search google, which pointed my in the direction of
http://damianblog.com/2007/02/22/webresource-but-no-emeddedresource/. However this did not solve the problem in my case. The solution for me was just as simple, you need to remember to set the default namespace on the project to the same namespace as in the Extender.cs file.
Hope this saves you as much time as i waisted ;).
Added By:
Lee Timmins on 12th Aug 2008 at 01:00
Last Updated: 04th Jun 2009 at 15:21