NavMeshSurface, cannot bake at runtime?

RuntimeNavMeshBuilder: Source mesh Map_10x10 does not allow read access. This will work in playmode in the editor but not in player
UnityEngine.AI.NavMeshSurface:BuildNavMesh()

GameObject cb = Instantiate(Resources.Load(GetResourcesPath(mapLayout.ChessBoardName)), Vector3.zero, transform.rotation) as GameObject;
        NavMeshSurface nm = cb.GetComponent<NavMeshSurface>();       
        nm.BuildNavMesh();

Solved.