Getting "Error fetching forums" error every day

[khildebrand]

Hello,
recently we upgraded our forum from very old 3.x version into 5.2.0. Everything went mostly fine, we translated it, made custom theme, but from time to time (well, sometimes even everyday) the home site of forum is unable to fetch the list of subforums and such. Subforums, posts, search etc. is working fine, but homepage shows "Error fetching forums".

When we see it, we go to "Clear system cache" and "Rebuild Forum Information", the forum works normally, but after some time the same error.

I was trying to look for people with similar bug, but without much success. It's especially weird since subforums are working fine, just the main index is looking dumb and users think entire thing went down.

[Trevor Hannant]

Replied to your ticket regarding MySQL Errors listed in the log you posted.

[khildebrand]

Thanks Trevor,we are trying to work on it.

[Wayne Luke]

Take your site out of debug mode. Does the error going away?

The error is generally due to invalid number errors in some records. We don't allow negative numbers. The developers are working on resolving this but it used to have problems for all users. As a workaround, they hide the error unless you're in debug mode.