Can someone from Microsoft please give this thread some attention?
I had exactly the same issue. I have been upgrading Atlas ASP.NET AJAX each and every time, and never had a problem.
This time I got everything working perfectly on my DEV box, and then uploaded to my PROD box. Then it gave exactly the same error message as people posted above. Turning on debug and trace did not provide any more detail in the error message.
The only way I could fix it was to deploy the source files, which I hate doing.
FYI, I am using the AJAX library, the Dec. Futures library and the latest Toolkit.
I need to get my box straight again. Please put some resources on this and help us out with a solution!
Thank you.