[TheLastSuperman]

^ Then it's a mod (or a single plugin) doing this.

I would not while in admincp do this:
- Disable the first mod listed.
- Now remove the disable hooks code from config.php and re-upload.

Is the forum still all wonky looking?
- If Yes then that first mod you disabled is not the culprit. Now re-include the disable hooks code in the config.php file and re-upload again. Now re-enable that mod. *Continue with this process until you identify which mod is causing the issue*
- If no then it was in fact that mod, leave it disabled until you find out why. Uninstall if you can't nor ever used it and no data was saved into your database, after all if no fix and you can't use it no use to keep it.

Anything goes wrong this article will help you get back into admincp (but for now the disable hooks code works just fine for you, keep using that for now this article is last resort if nothing else works ect) here is the link: https://vborg.vbsupport.ru/showthread.php?t=259619

Possibly Related:
- If your host has upgraded your PHP version (some do regularly with or without notice, hopefully they notify you) and older mods or plugins were written to work in older versions of PHP -OR- If something in the older PHP version is now deprecated.
- I've seen .htaccess files cause this. Usually if it works when config.php is disabled it's not .htaccess however could be if you're using vBSEO or DBSEO.
- I've seen template edits cause this. Including and/or not limited to javascript and other <style>css codes</style> and such.
- Of course mods and/or plugins as noted above.