The most serious one at the moment is that new users are unable to register. I've tested this
and what happens is the user gets a confirmation email, but when they click the link it tells them
"Your account is currently awaiting confirmation." Six hours later, no confirmation. I've had to confirm
I have "Enable Registration" and "Enable Email Confirmation" set in options > user registration.
There are other problems, but I'll take one at a time.