After defeating Diablo and receiving the achievements and such when an individual is given the options to click ok or cancel to exit the game if you click cancel and wait for another individual to click ok and the end game timer begins countdown, if you click the esc button to bring up the menu and exit the game on your own preventing the end game cinematic from playing the next difficulty will not be available, causing the user to have to beat Diablo all over again just to watch the cinematic in order to continue on to the next difficulty. I put a ticket in for this matter however i beat Diablo again prior to the ticket being answered and was capable of continuing on after watching the cinematics. All previous bosses had been defeated and all achievements were awarded. I was awarded the achievement for Defeating Diablo in nightmare prior to defeating Diablo for the second time. I am not sure if this is a reoccurring bug as i did not feel like having to beat Diablo a third time on nightmare.