ER Studio repository log in issue

Hello,

I'm getting the error below when trying to log into our repository via the ER/Studio data architect tool.  I've been a valid user in the repository for many years and just recently starting getting this error.  Does anybody have a clue as to what the issue is?

CORP\****** does not have permission to perform operation . The error returned by the Control System is: USER_NOT_LOGGED_IN.

Thanks!