The assembly with display name 'VJSharpCodeProvider' failed to load

Question

I added an AjaxToolkit:AutoCompleteExtender to my ASP.Net 3.5 application. The web service lives in the same web application. Now I am getting this error when I hit F5/Debug

Answer 1

I too have received the same error, but my solution was very different to all of the above. In the web config I had a reference to an Assembly Binding such that it was older than the version I was trying to load eg.

and I was trying to install version 4.2.3. I hope this helps someone!