Error: Actor::updateMassFromShape

I have seen other people post questions about this, but I haven't seen an answer that resolves my problem. I have an imported .fbx model that has many subcomponents. A couple of them have mesh colliders, but the object as a whole has a Box Collider. I tried to remove all of the mesh colliders from the subcomponents, but no luck, I still get the same error:

Actor::updateMassFromShapes: Compute mesh inertia tensor failed for one of the actor's mesh shapes! Please change mesh geometry or supply a tensor manually! UnityEditor.DockArea:OnGUI()

This error is making it virtually impossible to edit my scene because every time I try to move this object, my system gets clogged up with the same error message.