I don't know what it is but i had this happen 30 min ago... then i restarted my computer cuz usually that works... it did, i was able to get back in and then i quit to put some texture packs on... i log in, and then i go back to the title screen to change textures, and then it started giving me that error... so i don't want to make it feel like square one again but maybe it's not the server side? maybe it was and i just had bad timing....