Upgrading from 1.8.33 to 1.8.38 — anything to watch out for?

Spam registrations dropped to nearly zero after enabling a good Q&A challenge.

I switched the cache store to Redis and the ACP feels snappier now.

Make sure you take both a files and a database backup before upgrading.

Code: PHP

define('IN_MYBB', 1);

— always check for this guard in your own plugin files.

I did a bit of searching but could not find a recent thread on this, so here we go.