The courtyard outside of Rivendare’s room is broken. When you are killing the abominations they will instantly all disappear, and about a second later all of them will respawn. Killing all of the abominations will not cause the undead to come in, nor will it open the doors to Rivendare’s area. So you are forced to hearth out… I tried waiting 20 minutes to see if anything would happen.
I was able to recreate this twice in a row.
Did you die and then Soulstone res /Reincarnate or Vanish/Feign Death after starting the event (the event starts when you aggro the first abomb and the gates close)? If so that will bug the encounter. To avoid this you must die, release, and ghostwalk back into the dungeon then wait for the event to reset (abombs will all respawn and the gate reopen). For whatever reason that area and the event leading up to spawning Ramstein don’t like “wipe-protection” plays
I think I did. Damn dude.