I'll open a support ticket. Everything was running fine, in fact I was posting on the forums this morning, I've had these forums on this server since back in the Classic days.

These errors showed up this afternoon when I refreshed the main page. It's probably something my host has done. It looks like it's running PHP 8.0 (ea-php80), but I didn't upgrade it and it doesn't look like I can downgrade it like I used to be able to.