Code generated mesh not visible

Hi,

I'm doing a 2d side scroller and wanted to generate a mesh for the ground. I followed some advices from the net but I can't make the mesh visible.

I tried to solve it looking at the forum, I found many posts about but none of them solve my problem. I simplified the script to the moment where there is nothing else to simplify and it's still not working.

The mesh is not visible both in game and scene view (I checked while running the game). But when I double click the mesh in mesh filter componeni it is shown correctly in the preview window.

I thought it can be an issue of the graphic drivers but after updating them (i use Nvidia Geforce GT 630M) the issue remains.

The scirpt is attached to an empty game object (with only transform component). Code is very simple:

 public class PolygonTester : MonoBehaviour {
     private Mesh terrainMesh;
       
     private void Start()
     {
         Vector3[] vertices = new Vector3[] { new Vector3(0, 0, 0), new Vector3(10, 0, 0), new Vector3(10, 10, 0), new Vector3(0, 10, 0) };
         Vector2[] uv = new Vector2[] { new Vector2(0, 0), new Vector2(0, 1), new Vector2(1, 1), new Vector2(1, 1) };
         int[] triangles = new int[] { 0, 1, 2 ,2,3,0};
 
         terrainMesh = new Mesh();
         terrainMesh.SetVertices(new List<Vector3>(vertices));
         terrainMesh.SetUVs(0,new List<Vector2>(uv));
         terrainMesh.SetTriangles(triangles,0,true);
         terrainMesh.RecalculateBounds();
         terrainMesh.RecalculateNormals();
 
         gameObject.AddComponent<MeshRenderer>();
         gameObject.AddComponent<MeshFilter>().mesh = terrainMesh;
         
         MeshRenderer rnd = GetComponent<MeshRenderer>();
         
         rnd.sortingLayerID = 0; 
         rnd.sortingOrder = 100;
     }
 }

Could someone point me what else can I check?

Thnx