Game craches and/or disconnects

Hi,l I've just recently cleared THE WHOLE BATTLE WITH DOMINUS and my quest log shows mission complete. But when I killed him the game crached and I loged in again. but every time I try to enter dominus battle room the game disconnects, wtf? Fix plz. Since I cant enter the room I gues I cant advance into the next difficulty which is game breaking.

have the exact same problem, first time i entered the boss room i crashed, ran back entered again and killed him then the game crashed now i have tried to reenter 17 times and it wont let me in the boss room.

happens to me aswell, cant enter the room