Can you tell me which upgrade sends you to the main menu? Tried it myself when it was the only one left, also go to your computer, developer tools, and press hide all screens to get rid of the 1st and 2nd floor icons
At first it was the kitchen upgrade. But once the extra room upgrade was available, it became that one. When I tried to buy the extra room upgrade, it instead bought the kitchen, so the extra room upgrade became the problem one.
