I added a train mod in my saved game. I used it for few years and then sold it. Now I am no longer using that mod. But when I remove it from my saved game, it shows error. The saved game has still reference to that mod even I am not using it.
I want to remove it because I want to upload the saved game and don’t want users to download additional mods for my saved game.
Once you have added a mod to a game, it becomes part of the structure of the saved game. If you try to remove the mod the game will crash when you try to start the game, it will be looking for non-existent resources. This is how the game works.
NB: This does not apply to purely graphical texture mods such as the winter snow (Frosty November) type mods that can be added and removed at any time.