Unity – using Colliders with custom objects

Hi so I’m quite new to Unity and currently experiencing issues with colliders, a quick summary of what I have.

Player >

Object = Capsule ( Directly created through Unity ) Components = CharacterController, CapsuleCollider & a PlayerController script 

Basic Tile >

Object = Rectangle ( Imported from blender ) Components = BoxCollider 

this combination works well, no issues. However when I get to slightly more complex objects, such as elevated terrain I can’t apply a box collider because the surface isn’t flat. So my next thought was to add a Mesh Collider but unfortunately it doesn’t seem to do anything effective ( my player falls through ) I don’t know whether that’s because Mesh Colliders are only relevant to RigidBodies? Unfortunately though I can’t switch from a CharacterController to a RigidBody.

So I’m not sure what to do, maybe MeshColliders are reponsive to a CharacterController and my settings aren’t adjusted correctly?