There is a bug with the nightfall where if you respawn on your own while fighting the boss, you will respawn to the last floor that had adds prior. When trying to use the teleporters to get back up to the fight, you will hit a kill wall immediately after using the launcher and cannot rejoin the fight.
Not sure if this affects all versions of the NF, but this was on Prestige Difficulty.
-
Hi, Thank you for your report. We are tracking this issue and currently investigating.