celinanananah A green outline only means that the household has enough funds to purchase it. That applies throughout the game for any type of lot when you attempt to buy or move in. Thanks for the pic. That means that the issue is down to the lot. So, since you built it and the game doesn't allow it to be purchased, that means you've missed a requirement or haven't properly defined the apartments. That's about all it can be at this point. So, you need to take the lot back into build and find and correct whatever is causing the issue. Check to make sure that you have accessible routes to each apartment as well.
Idk, if this has any bearing on the issue, but when I buy an RR, I only travel with the one sim who is buying it, not the whole family. You might try that before anything else to check if that might be what's causing the issue. I don't think so but you never know with this game sometimes.
Just by chance, I I happened to buy a residential rental yesterday in my own game. I didn't have any problems. So, from that, I know there is nothing wrong with the game itself. That's an indication that the problem lies in your save and/or the lot.
Hope this helps.
