Takes place during Halloween in Pennsylvania, yet all exterior scenes show green foliage on trees/shrubs.
According to the opening voiceover, this episode takes place on "October 30, 1980-something," yet Adam's Beetlejuice costume includes LED lights that did not become available until the mid-2000s at the very earliest.
When talking to Erica Barry puts his backpack on backwards and that's why it falls off immediately afterward.