can't paint wall or choose any type of wall options

Hello,

Help, upon on build mode, there two problems with the game. So I move the household from normal house to apartment. I choose to bulldozed the lot and start from scratch. 

1) When I created a room, I realize that the exterior wall is unpainted. So how do I painted it again? I can just google it. lol

2) Upon cloning the wall I want or choose any options of wall, there is no catch at all, it catch the flooring on the next room instead, which in bb I always put the wall up. Seems like the wall is invisible or something. I even choose the wall and try it on the room that is not connected to the exterior and it say 'nothing to change'. And when I try to paint in the wall that is connected to the exterior it say 'cannot make changes outside area'

I even test on other household too and it is same problem.