Tested with Repentance+. If any problems arise, please notify me!

• I AM ERROR rooms can now spawn a hanging dream catcher.

• Actually updated the mod correctly this time 🙄

A longstanding crash has finally been found and fixed!

• Fixed a Co-op related crash when playing on non-english languages.
  
  • Thanks to this user for the help!

A general cleaning/refactoring of the mod

• Replaced the method for checking XL Boss rooms with a built-in method (Many thanks to Stlkngne for the information!)
  
• The dream catcher should now stay when re-entering rooms (for good this time!)
  
• Revised spawning criteria for the dream catcher
  
• Removed an unnecessary 'cleaning' method

• Revised the entry of the hanging dream catcher in the entity-list 'entities2.xml'
  
  • This should not have any significant gameplay changes, but it does fix an annoying warning being spammed into the game log

Small quality of life change

• A hanging dream catcher will now spawn in the second boss room of a Curse of the Labyrinth! floor instead of the first room

More requested changes :D

• An additional hanger will spawn in the Alt. path room following a boss fight (for those who are REALLY forgetful!)
  
• Picking up a Dream Catcher after beating a floor boss will now spawn a hanger in the cleared room
  
• A hanging dream catcher will no longer spawn after Isaac/Satan

Several changes made (mostly from your comments!):

• Checking for the item now primarily uses the ID of the Dream Catcher and not its english name, this should hopefully fix the mod not working with language mods
  -- Thanks to Romzes for creating a solution
  
• The hanger will no longer appear after most 'final' bosses (i.e. the ones that spawn chests instead of trap doors)
  
• The hanger should now actually spawn in Greed Mode, for those who care :D