Ajax client-side framework failed to load Asp.Net 4.0

Question

I got a complicated problem with ASP.Net 4.0 Ajax....I started a website with Visual Studio 2010 on my machine,and added some update panels they used to work fine,but sudden

Answer 1

I had the same problem and I solved it by run the command aspnet_regiis -i on the folder of the Framework 4.0 (on which my application ran). It was a problem on the Handler Mapping of IIS: this operation fix the problem for me. See also this post.

Hope this could be helpful.