This is the error that I am getting (I use a ajax toolkitextender):
I tried to solve this error with this thread: ASP.NET Ajax client-side framework failed to load. when put the ScriptManager on a blank page
But nothing worked..
Can someone please help me, can't use any ajax toolkit extender...
On my other website application it all works, but in this new one everyhing goes weird....
Found the answer.
Because I am using URL rewrite in the Global.asax file, I need to add this to the application_start: