Created attachment 152 [details] My character walking through the invisible, glitched wall. 1. Build a house with at least 2 floors using the apartment background. 2. Enter a session and change the dimensions of the bottom floor (in my case, I added a back room). 3. Somehow, this breaks a wall of the outside of the bottom floor. The wall is invisible, can be walked through (the character does gain some height and float when doing this, but it resolves in the next room) into the room behind it, and messed up any related things, such as the house missing geometry on the ground.
Created attachment 153 [details] Here's what the broken wall (near the air conditioner on the right) looks like from behind from the 2nd floor. The room its attached to is invisible. Further showing what this glitch does (part 1).
Created attachment 154 [details] Here's what the base of the house looks like on the ground in the land. Further showing what this glitch does (part 2). The base of the apartment is completely invisible from the other angle. As is, this angle is still missing things.