>>WebResource.axd is an HTTP Handler and it's mapped to IIS without a file requirement - ASP.NET generates the response for this. I doubt the error you are getting is related to the AXD file not firing - ASP.NET uses this resource handler in many places.
>
>I'll see on the next .NET Framework if this will get better. Probably something didn't get installed correctly and this might cause this situation.

I doubt it. If WebResource.axd doesn't work all sorts of stuff simply won't work...

You can check for the AXD script map in IIS. It should point at the aspnet_Isapi.dll just like .ASPX, .ASMX etc. All these extensions install at once so there's no reason for one to be missing.