In the Labyrinth of the Ancients, during the final boss fight against Acheron, several mobs called Iron Claws spawn through the fight and grab onto a player. When they do, the player receives a status ailment (I can't remember the name) that immobilizes the player and makes them take damage over time until the claw is killed.

The glitch comes after the fight. If the boss Acheron is killed while an Iron Claw has hold of someone (and they have the debuff on them), after the fight there are times that the player will still have that debuff on them even though the claw has disappeared. The fight is over, but with that debuff on them the player still cannot move or take any actions and takes damage over time. The only way to get out of this is to die and get raised, or to select Leave from the Duty Finder menu. I have had this happen to me on both the PS3 and PS4 versions.