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 encountered the same issue. It happened to me when I attempted to attach to a process for debugging purposes. At the time I had postponed a pending windows update.

Everything started working fine after I restarted my computer and allowed the update to take place.

Additional notes: I had recently updated to Visual Studio 2010 Ultimate and installed its Service Pack 1.

Answer 2

Simply. Restarting Visual Studio solved the problem in my case.

Answer 3

From what I can tell when I'm able to reproduce this error, it is caused by being in the middle of installing Windows updates. So, running updates, then postponing a reboot, then attempting to debug code is what was putting me in this broken state.

Answer 4

I also updated to Service Pack 1, and made sure Windows updates were up to date, but I was still having the same issue:

"The Version of CLR.dll in the target does not match the one mscordacwks.dll was built for."

Microsoft closed this issue on connect.microsoft.com as not reproducible... Unforgivable, irresponsible support system!!

But on social.msdn.com I was directed to upgrade through this link, and this has resolved the problem in my machine ( Win7,VS2010,target 4.0)

Hope it helps.

Answer 5

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.