Scale and save prefab

Hi

I'm trying to scale a mesh and then save the GameObject as a prefab. The scaling works fine but after saving the prefab the prefab's MeshFilter is always empty.

Testing steps are:

1. Create a Cube (GameObject > 3D Object > Cube)

2. Attach the Script to the Cube

3. Play

After this i can see the Cube is bigger and the prefab is created but when i check the prefab it's MeshFilter is empty.

 public class ScaleMesh : MonoBehaviour {
 
     public float XScale = 3.0F;
     public float YScale = 3.0F;
     public float ZScale = 3.0F;
 
     void Start()
     {
         Mesh mesh = GetComponent<MeshFilter>().mesh;
         mesh = ResizeMesh(mesh);
 
         PrefabUtility.CreatePrefab("Assets/" + gameObject.name + ".prefab", gameObject, ReplacePrefabOptions.ConnectToPrefab);
         AssetDatabase.Refresh();
     }
 
     Mesh ResizeMesh(Mesh mesh)
     {
         var baseVertices = mesh.vertices;
 
 
         var vertices = new Vector3[baseVertices.Length];
 
         for (var i = 0; i < vertices.Length; i++)
         {
             var vertex = baseVertices[i];
             vertex.x = vertex.x * XScale;
             vertex.y = vertex.y * YScale;
             vertex.z = vertex.z * ZScale;
 
             vertices[i] = vertex;
         }
 
         mesh.vertices = vertices;
 
         mesh.RecalculateNormals();
         mesh.RecalculateBounds();
 
         return mesh;
     }
 }