Arena bugged (act 4 cruel)

So I was playing on cruel act 4, and first of the grand arenas was bugged as such - i killed all mobs but there still were no way out of it, I could only go back. Its either that or the exit was in such position I couldnt click it.
Bug ID number: 2 685 870 282 (also in last screen)
Rest on screens:

It's a dead end. There is no hallway to continue down, so you go back the way you came.

Must have missed the other way then, tho i checked. Thanks!