Unable to send request, 33, The handle is in the wrong state for the requested o

I am running MF on a Tagadab VPS for a couple of years now and never had issues. This afternoon the above error messages came up and still does. I have rebooted the server, installed a new version of MF but all to no avail. Any clue what I can do about it? Up to yesterday everything worked fine. 

Thanks!