I am in the process of building this High Rise, and have come across this problem. This first screenshot is just after finishing making the exterior of the building, and before I click 0 to jump into Camera View. The selected object is my camera. No problems yet!
This next screenshot is after pressing 0 and panning out of somehow being zoomed into the interior (clearly the camera is outside and is not even facing the interior...) and now one of the sides of my building is missing?! I also tried messing with the camera's Focal Length which didn't work, and the outsides of the camera view aren't blacked out like they're supposed to be.
And third, the missing wall mesh somehow ended up floating in space all the way over there...
Any idea what the problem here is? Thanks so much!