Operation could not be completed message when trying to open Linq to SQL (dbml) designer

That was really strange.

The annoying Operation could not be completed error message appeared each time I tried to open the dbml designer.

I did some search and found that I need to start the Visual Studio 2008 Command prompt and type the following command:

devenv/resetskippgs

But this didn't helped a lot. The annoying message was still appearing.
Then I found something which made me laugh. It was so unexpected...
If you had the same problem and the devenv/resetskippgs couldn't resolve it, try going to Control Panel -> Administrative Tools -> Event Viewer.
Select the Application node and right click it. Then delete all events.

This would hopefully resolve your problem.

Funny isn't it?