Everyone that is freaking out over this bad login thing, calm down. The Mojang Session server is down, so people that were already on when it crashed were able to stay on. None of the premium servers work at the moment because of it. http://minecraft-techworld.com/status That link shows what servers are up for Mojang, to test and show that it's not just you. The fix: No fix, you just have to wait it out.