After recent cpanel update, I started getting the following error while accessing horde webmail.
This problem is expected to be fixed before cPanel 11.51 becomes 11.52 and is published to CURRENT, but it is still occurring in the 11.51 build that is in EDGE right now. The temporary fix for that problem is as follows.
Now, move or remove any files that are listed by the above find commands. I recommend that files be moved, and not removed, to be on the safe side.