Feedback my Instantiate is broken

what should I do?

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. public class NewBehaviourScript : MonoBehaviour
7. {
8.     Transform tr;
9.     public GameObject ground;
10.     public int groundlength;
11.  
12.     void Start()
13.     {
14.         for (int i = 0; i < groundlength; i++)
15.         {
16.             Debug.Log("hello");
17.             Instantiate(ground, transform.position, Quaternion.identity);
18.         }
19.  
20.          
21.  
22.      
23.     }
24.  
25.  
26. }
27.  
28.  

image:


I don't use the instantiate command, this is ok