Possibly Story Related
You might get this just playing the story, but to be safe make sure to serve the correct drinks that they request. I have a list of all the drinks in Master Brewer guide.
For this Arc to end happy you need to:
1. Serve the correct drinks to the Werewolf and Vampire.
2. Serve Gala the Gala Had tea/milk/ginger when hes a Werewolf.
This insures that Gala shows up at the last game segments. Also results in the happy ending arc.