I've included a few new extensions. All forums need to be synced now, because the file structure for them had changes a bit (some extensions moved their files, new ones were created, etc...). What this means is that most forums will report a 50x error when you visit them. You can "Fixup your forum" via https://freeflarum.com/settings/forum_settings, which will sync your forum earlier. Or, you can wait approx. 2-5 hours until all forums are synced.
@Equinemarkt I've synced your forum, the error should be gone
