Hello konf,
I guess you mean, if you update a building, you will see 2 buildings. The old one, and the new one overlaping the old model, right ?
This happens often if an lua error occours inside the upgraded building.
Totoal mayhem is not changing anything related to upgrading structures.
Do me a favor, start the game with only Total Mayhem activated. Deactivate all other mods.
If the error still happens, please tell me:
1. What Gameversion are you using ?
2. Where did you install Total Mayhem (full disk path)
3. Post the game error.log. (use
https://pastebin.com/ )