@Ophiethebird
Since you are playing with mods and CC, the proper way to test a problem like you're having is to take the mods folder completely out of the game path. Using the Game Options and unchecking the boxes but leaving the mods folder in place isn't enough to keep a lot of things in the mods folder from being picked up anyway when you quit and restart the game. Another thing is that some mods will leave residual code behind attached to a build object on a lot even if the mod have been removed or deleted.
To make sure the issue is not mods, just drag the mods folder to your desktop and then start the game. Go to the lot where you were building and enter it from the map and see if you still have the problem, if you don't, it's something in your mods folder and you'll have to find and remove the problem causing file. If you are still having the issues after testing that way, you can further test by dragging your user folder (The Sims 4) to the desktop, start the game, go through making the sim and placing them, then test a few lots, going to them from the map, to see if the problem shows up in the new folder, then save and quit. It probably won't but if it does, then do a game repair or a full uninstall/reinstall. Then copy the saves folder from the original user folder to the new one and restart and load the save and check the lot and a few others again. If it works, then try copying your mods folder from the original to the new user folder and test again. If it comes back, then again, it's something in the mods folder. If it doesn't, then it was something in one of the other folders like a game override.
If the problem is only on that one lot, then there may be something on the lot causing it. Crashes can leave residual code behind sometimes so if your game crashed or you did a hard reset with the lot open, that could be the cause and the only way to fix it is to bulldoze the lot or load another lot on top of the one that is there, replacing it. Either way, you will lose everything on the lot and will have to start the build again from scratch. If the lot was a gallery download, there are a lot of lots in the gallery that cause problems for those who download them and it could just be something like that, so you'll just have to find another lot.
If the problem is on most or every lot in that save, then other things you can try if none of the above works is to try a game repair or a full uninstall or reinstall. But tbh, if the problem continues even after doing everything I mentioned above, it might be the save is corrupt and you'll have to start over in a new save to get things to work properly.
Hope this helps.
