So... apparently, it took me two days to completely broke the game
No matter what objects I try to put in the lot, the game turns them red color (unpleceable) and doesn't allow me to put them down.
I have 800 money, so it's not a problem of not being able to afford stuff. Counters, beds, paintings, decorations... I can't place anything down, even if there's a lot of space and no other object in the way.
(currently having a birthday party)
(tried to clean the cache, but it didn't change a thing)