Steps to reproduce:
- Pick up The Haunting from Elenor in BM
- Go to the past for the first time and save the lady from the basement
- Mission text updates to “Touch the mirror in the attic”
- Run to the mirror ignoring The Butler and touch it
- You move to the next time period with no mission text and no way to advance the mission. Congrats, you are now broken and have to teleport out and pause the mission in order to be able to do anything.
Seems that skipping The Butler will break the mission even though the text never says to fight him nor does it prevent you from using the mirror anyway.
Edit: I guess you can use the mirror again to exit, but that’s not the point.
Edit 2: Picking the mission back up puts you at 3/5 where you should have been before the mission got stuck.