What is going on with the website? Is it down? First I couldn't log in, couldn't send a "forgot password" request, couldn't create a new account, couldn't even email them in the "contact" form they linked. I finally managed to log in, but now I'm getting the same exact error message when I try to publish my game. What the heck is going on, how can I fix this??

Could be a temporary issue. Or could be that you have http:// instead of https:// at the start of the address.