It's March 2018 by now and this bug is still a thing. Just discovered it today at the Landgraab IX Apartment. In the 2nd story, a few of the exterior textures get deleted, regardless how you edit the inside. It does only aply to the area @nathangecan mentioned and only (at least for me) when the room connecting directly to it gets edited.
It doesn't seem to be solved yet, does it? Or does it have at least a workaround?
March 2018 - last edited March 2018
I'm sorry @QuinceyID. I just did some additional testing and experimentation, but I found no way to work around the issue.
Product: The Sims 4
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What is your current game version number? 184.108.40.2060
What expansions, game packs, and stuff packs do you have installed? Seasons, Cats and Dogs, City Living, Get Together, Get to Work, Parenthood, Dine Out, Spa Day, Movie Hangout, Laundry Day
Steps: How can we find the bug ourselves? 1. Enter build mode on the lot 1312 21 Chic Street (Penny Pizzazz's apartment) 2. Either destroy, rearrange, or repaint any of the walls connected to the kitchen room 3. View the exterior wall of the apartment.
What happens when the bug occurs? When any modifications are done to any of the interior walls of the kitchen room of this apartment, the exterior wall is affected. It removes the wallpaper that is already on the exterior and becomes blank. It will no longer match the wall color of the rest of the apartment exterior, which cannot then be edited due to the exterior of apartments being uneditable.
What do you expect to see? The exterior of the wall should remain the same wallpaper regardless of modifications that occur to the interior. The wallpaper it should normally be is titled "Large Fancy Wall Tiles" from City Living.
Have you installed any customization with the game, e.g. Custom Content or Mods? Not now. I've removed them.
Did this issue appear after a specific patch or change you made to your system? Neutral/Not Sure
Screenshot 1: This is a normal screenshot before making any modifications. As pictured, the exterior is painted normally, matching the rest of the apartment/building.
Screenshot 2: Now, after destroying a wall piece, the exterior of this apartment is now blank. This now cannot be edited without undoing any modifications to the room. Because exterior walls cannot be painted either, this wall piece remains blank.
Screenshot 3: The same bug can be recreated by painting any wall piece in the kitchen room. Again, the wallpaper is different from the rest of the exterior and is unchangeable.