I'm not updating anything that should affect forums but there's always a chance they'll be unavailable briefly during the process, so it's best to avoid uploading files, and while it's happening it's a good idea to copy your post(s) before submitting just in case.
I'll try to remember to give a 15 minute warning, and then update this thread when finished, but it wouldn't be the first time if I forget
Update: Updates should now be complete. I'll leave this announcement up for anyone to report anything that seems broken since updating, and I'll probably do what I usually do and forget to get rid of it until the next time I do some updates
