MyBB Community Forums

I got this SQL error each time upon trying to create or delete threads.

The issue turned to be that I recently uninstalled the (pre-1.8) plugin "Thread Count Pro" that used the custom column 'threadnum' in the 'mybb2_users' table as part of its operations and dropped it as part of its deinstallation.

Unfortunately, MyBB 1.8 seems to have used this column on a regular basis to provide for the user thread count, so its deletion caused the problem.

The solution was to recreate the column in the database, something like:

ALTER TABLE mybb2_users ADD threadnum INT NOT NULL DEFAULT 0

and then to recount the user thread count in the ACP.

Hope this helps.

This is why you need to be careful when installing a plugin for 1.6 on a 1.8 forum. While you can trick the system into accepting it by changing the compatibility line, it may have issues because of things that have changed.

No, I did not install a plugin for 1.6 on the 1.8 forum. On the contrary, I uninstalled this plugin ;-)

The plugin was deactivated before installing MyBB 1.8 (as it was suggested in the documentation), and then, after MyBB 1.8 was in place, I uninstalled it. The documentation did not say that we should uninstall all plugins before installing MyBB 1.8. It advised only to deactivate them.

The pb I think is exclusively in that the "threadnum" column name has not been sophisticated enough to not accidentally match something used in old plugins.