The integration add-ons installed for Flashchat are meant for earlier versions of the board software. Since we upgraded, the integration broke, and now logging in is, at best, hit and miss.
I can't log into the Flashchat either. In order to try and get it working for everyone, I'd have to upgrade it.
EDIT:
Alright. Trying to upgrade it broke the site, and still didn't let me log in.
For right now, I'll try to look into it more, but until it appears otherwise, the chat should be assumed to be non-functional. If you can get in, great, if not, it's not intended for this version, but the upgrade doesn't work right either.
ANOTHER EDIT:
Weirdly enough, I was able to log into the Flashchat with my testing account.
YET ANOTHER EDIT:
Ok, you may want to try it now.