DD got the main dollhouse for Christmas and some rooms from other relatives. Today we tried to add the rooms to the house, and it doesn't connect. After googling, frantically searching the house and recycling for non-existent ledge pieces, then further googling, it transpires that we have the movie addition house, which has an entirely different connecting mechanism, so isn't compatible with the standard rooms she has.
The boxes are completely destroyed, so no chance of returning them and swapping for compatible rooms. WIBU to hot glue the bits we have in and hope she loses intrest before my bodge fix brakes.