Unable to Save DCR

System

I am having this strange problem. One of the "Master" user is not able to save any of the DCR. When he tries to do it he gets the following error.

The DCR "path" has failed to save. Could the file be locked by someone else in the same workarea?

The file is not locked by anyone. Even tried unlocking and then saving the DCR. This is particulary happening only for one user. None of the permissions have changed.

Any ideas?