It happened to me last night. Can't enter, the game stuck on loading screen, the bar is at 80-90% i think, and remain there forever. I had just beaten underworld madness boss and got three golden skull in every level, now i'm really afraid i have lost everything (in which case, bye bye game, i will never restart from scratch). I could send an email to assistance, but i don't remember the exact account name (only the name, not the numbers)... sigh T_T