One of my buildings creates a UI Exception

Hello,

I've built a house in Sims 4, no mods, no CC, and I've got the ‘for rent’ expansion pack amongst others, so I want to make it a residential rental lot. The problem is when I change the type and save it, there is an error happening, and the game loads forever. When I close the game and come back to the city, the screen is blank, and the city never loads. I tried this with Willow Creek and Tomarang, and it's the same. 

If I go back to a previous save, before making the lot a residential rental lot, it works perfectly.

When the problem happens, I have a new lastUIException file saying something like that :

TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at widgets.GameEntry.Neighborhood.controls::NeighborhoodMap/HighlightLotsEdit()
    at widgets.GameEntry.Neighborhood.controls::NeighborhoodMap/SetNeighborhoodMode()
    at olympus.core.widget::WidgetBase/Show()
    at olympus.io::CommunicationObject/DispatchToWidget()
    at olympus.io::CommunicationManager/DispatchStoredOnDemandMessages()
    at olympus.core::LayoutManager/OnDemandWidgetLoadComplete()

I didn't use any mods or CC, only move objects to place a few things, so I really don't understand what is causing all this. 

I spent a lot of time building it, so I really hope someone can help, and I won't have to start all over again... 

Thanks a lot.