MyBB Community Forums

I tried searching and found some old results but nothing seemingly relevant. I just upgraded to PHP 7.2 and suddenly, forums can't be marked as read (though threads still can). No combination of the mark all forums read link, clicking the indicator on the index, or viewing every thread in a forum seems capable of clearing the unread status. This worked prior to the PHP upgrade but another MyBB install running the same version and on the same server continued to work fine post-upgrade.

In my testing, I've found that it only seems to affect users that have been active as my test account was unaffected. It also seems limited to my custom theme as switching to the unmodified default does not exhibit the same behavior. I've dug through code and templates for the last few days though and I can't seem to figure out where the issue is coming from. If anyone can shed some light, it would be most appreciated.

Thanks!

Edit:
Oops, forgot to include a link. The forum in question is at https://www.vgfacts.com/forums/

Apologies for the double-post but as this has now fallen off the front page and still hasn't received a reply, I'm just looking to get it a bit more attention (hopefully from one of the support staff).

As mentioned, this problem started after an upgrade to PHP 7.2 but only on one of two MyBB installs on this server and even then, limited only to one theme on that one install. All post tokens match between the working and non-working theme and no errors (visible or in the server logs) are thrown when attempting to use any of the mark read features. I've tried truncating the threadsread and forumsread tables and rebuilding the caches all to no avail (not that either of those would necessarily make sense given that it works in the default theme).

If anyone has any ideas at all, I'm all ears as I really can't figure out what's going on here. Thanks!

mark read link should include {$post_code_string} (footer template)

<a href="{$mybb->settings['bburl']}/misc.php?action=markread{$post_code_string}">{$lang->bottomlinks_markread}</a>

It does but thank you! I narrowed it down to a custom function after a ton more testing (I posted my previous reply in the midst of that testing just a little too hastily). It took a while but I found where I wound up breaking it and got it resolved. All the same, I appreciate the very quick follow-up on your part, .m.!