So... I've recently instaled three mods and one of them is blocking the CollitionBoxTolerance for XXL. This is my main suspect, since it's a very old mod for XL. Ploppables - Wall Collection 1 I've also installed other two mods recently. Both are for XXL so I doubt these are causing the trouble: Ploppables - Trees - XXL - author original: Jrvieux Ploppables - Furniture Mega Pack - by timofp - XXL Now, I know I should delete every single piece from the Wall Collection i've placed in my city and then remove the mod from the mods folder. I've tried it, but the game crashes. I really don't know if I accidentaly placed one piece of wall underground, so it's unreachable at this point. I haven't tried to remove the XXL mods since I don't think these are causing the problem. But I guess anything is possible. Can anyone help, please? It's a pain in the ass to work without the CollitionBoxTolerance. I've been working on this city for two months now and I don't want to start all over again. Thanks!