The version of clr.dll does not match the one mscordacwks.dll was built for

Question

I have a C# console app in Visual Studio 2010 that I can run just fine. When I attempt to run the process in debug mode, I am presented with the following error:

Answer 1

I had this issue once and it was caused by an pending Windows Update on the Server where the process was running, which I wanted to attach.