Was getting some kind of connect/disconnect error while trying to log in yesterday, finally managed to work my way past it to get in.
When you first start to sign in, 2 pop-ups gen, #2 a second or so after #1
Leave them alone until the bar progress has stopped (mine was 40%).. then close the top most pop-up.. the 2nd SHOULD close on its own, and the process will restart.
DON'T touch anything.. even if more pop-ups appear.. the progress bar should continue past/despite them. If you have to close a pop-up, do so. Keep trying like this and it should eventually let you in.