It's cause of the session is down [There is a problem with Mojang]
Look at this site to see when It'll come back up http://xpaw.ru/mcstatus/
Rollback Post to RevisionRollBack
Welcome to my signature! I'm on the forums almost everyday (even if its just for a few minutes) So if you have something to tell me or tell me about, just send me a PM (private message) Note- I do not usually check the places I post to see if there are replies, so the above applies. ~Notch
Look at this site to see when It'll come back up http://xpaw.ru/mcstatus/