Not sure if anyone else has come across this yet but I'm finding it impossible to log into anything that requires a login on my pro. It's happened to my girlfriends pro also, I upgraded them both in the same day. Basically the list is: iMessage, FaceTime, Facebook, amazon, twitter, hotmail - anything that you need to log into. No error message, just loading icons on ML based applications and the loading bar just freezes on both safari and Firefox. Seems strange that it's happened to both pros? Couldn't log into this on my pro, so managed to post this on iPad which logs in fine apart from iMessage which I tried logging out of to log back in to help solve the problem, same for iPhone. Any ideas, anyone?? I'm stumped, and a touch frustrated! We now have two Macbook pro's that are useless. I don't use any sort of password manager, have tried a keychain first aid - nothing there and had a sweep for any virus - still nothing. Can anyone help?