User unable to access UserCp?

[TopShelfGamer]

I have a user who cannot access his user cp.

When he clicks the link it says Invalid specified. If you followed a valid link, please notify the administrator

I logged into his account and got the same error message.

I can backtrack my way to his user cp but when i goto save any changes made or anything i get the same error message.

i have tried changing his user group and all of that already as well trying to eliminate possibilites.

Any idea on what would cause this or how to fix it?