Tank going through mesh colliders, but not box colliders

I have a drive-able tank that I made and I have a few objects. some of these objects have box colliders, which blocks the tank just fine. But any objects with a mesh collider, the tank is able to force its way through it. I also tried making the object static but it didn't help. Mesh Colliders also seem to work fine on regular cubes, cylinders etc. but for my custom objects it doesn't. Anybody know how to fix this?

 

Does your tank have a mesh collider on it? If so Unity does not support mesh collider to mesh collider if they are non convex.