Map does not exist

[Mudbill]

Open the level that has the door that crashes you. Select the destination map again. Perhaps the issue is related to the fact that the map was first set before you made these name changes to your story.

Another thing you can try is to open the map file with a text editor and search up "custom_stories/Ninth of October - Continuation/Maps/C:/Program Files(x86)/Steam/steamapps/common/amnesia the dark descent/custom_stories/His dearest friend/Maps/Mansion_2.map" and see if you find that line somewhere. You can then edit it. Just be careful editing the map manually this way so you don't mess it up. I recommend a backup.