I'm a little embarrassed, but I already had to patch the brand new Case Closed DLC. Here are the changes:

• New Final Boss Fight:
  • 1st phase: projectiles should no longer appear in the crypt after being struck
  • 1st phase: wall and switch now reset after each attempt
  • 2nd phase: electric bolts weren't hitting the player. Now they do! Also slowed their pace to make it a bit easier.
  • 3rd phase: demons should now reset after each attempt. They will no longer "multiply"

• Snake / Secret Room
  • Snake should no longer block exit after returning to the surface from the puzzle
• Arthur ghost
  • should now disappear after showing him the hat
  • should no longer re-appear on entering the parlor room
• Portrait Room:
  • fixed: candles not opening secret door after turning them off in the correct order
• Dock:
  • fixed: boat magically appearing at the dock ladder before it has been repaired.
• Other:
  • not returning to a certain "demonic" room after loading save

That's all for now!