Several users with errors today

Hello: Today (5/11) several users are reporting problems logging into
GroupWise and/or starting notify. The error is: "The application failed to
initialize properly (0xc0000022)". We has no problems yesterday. We run
GW6sp4 on NW6sp4. I have run system maintenance on the domain but that did
not help. I have confirmed that it is not the user's workstation, and the
problem travels with them. I even restarted the GW server to see if that
would help.

So what is up with this?? Looks like it is a problem with user objects??
How do I fix this??

All help greatly appreciated, Chris.