Blender Walk Cycle in Unity not going down slope?

I've created an armature in blender using "Rigify", made a walk cycle animation and exported it as an .fbx to Unity. The walk animation works fine when going on a flat surface and to make it go up a slope I simply added a character controller but it does not go down slopes. I've tried added a rigidbody but that does not work, it just keeps walking straight through the air. When I add a mesh collider and select the model, it just falls over. adding a capsule or box collider has no effect.

When I generate colliders, it give mesh colliders to a bunch of empty gameobjects inside the model