The largest airplane hangar in the game with the massive accordion-style doors in the front that do not shut or open, there is one at the NWAF on Chernarus and the military airfield just Northwest of Gliniska on Lavonia, has an invisible step up on the roof on the left side of the building if you are facing away from the front doors. If you get up onto the roof, from the right side, and start walking across it to the opposite end, about halfway across your character steps up even though it is a flat roof. This is causing major issues in the placement of fences or watchtowers. You can only build a fence along the very front edge of that side of the room because of this invisible step up. And it also seems that along the entire length of the roof, your character seems to be walking just above the surface of the root and not directly on it by maybe a foot or so. That also makes the fences or watchtowers that you are able to build about a foot or so above the roof at the bottom. I would be happy to explain this in more detail if you need me to but I hope that this is enough. Thank you so much for all the hard work that y'all do!