Can't Log Into My Forum All The Sudden, Error!

[Morpheo]

An odd thing happened with my forum during my vacation. I came back from vacation and now I cannot log in as Admin and many of my users are reporting that they cannot log in as well (although some still can).

When I try to log in as Admin, here's the error that's given: http://screencast.com/t/OvJGwrYX

The login fails and I do not have access to the Control Panel.

What can I do in this case?

There were no updates made during my vacation. Before my vacation, everything was working perfectly. It was only 1 week ago that things worked fine.

Was I hacked?

[AndyF]

I'm assuming you are 'self hosted' ? If you are a using a Cloud account please submit a ticket in the Client Area

If you are self hosted, ask your host if they have changed anything lately in particular php versions.

If you are not sure /in doubt: I'd suggest actually just opening a ticket in the IPS Client Area anyway and a support tech will be able to advise you if it is a hosting related issue or otherwise.

[Daniel F]

That's an issue with a plugin. Was really nothing installed or upgraded while your vacation?

[Morpheo]

I am self-hosted.

If it's an problem with a plugin, how can I uninstall it manually without using the Admin CP?