Ok so, every time i open Minecraft, it works fine, no laggyness or anything. but when i try to load onto a game it just says "saving world file" or whatever it says on the loading screen to go into the game, and eventually crashes Minecraft. maybe this has to do something with my name change? it never happened before, it just started happening as soon as I changed my name from CryGuy to jjud_.     please help! I wanna get back to the gaming.