When I came to play Minecraft on 1.7, I clicked play and the loading bar on top of the Play button stayed empty, after like 20 seconds, the blue part of the bar which represents the progress on logging in went to the middle of the bar, it stayed there for like 50 Minutes after, it went to the end of the loading bar and then the loading bar vanished and I tried to click the play button again, it was frozen but I was still able to click the other buttons exept the Play button.