My programming says "The referenced script on this Behaviour (Game Object 'explosion_asteroid') is missing!" although my Scripts works fine.

I made a shooting Game from Official Unity Video(https://www.youtube.com/watch?v=2KRLVRPdoKQ) and When I made a script that explode asteroids when it hits to the laser and spaceship if spaceship collide asteroids, but when I run the game there are errors of "The referenced script (Unknown) on this Behaviour is missing!" "The referenced script on this Behaviour (Game Object 'explosion_asteroid') is missing!" "The referenced script on this Behaviour (Game Object 'explosion_asteroid') is missing!" I already research this errors on different websites but I didn't understand well to solve this problem. I want to know the way to solve this problem of reference and instance.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class DestroyByContacts : MonoBehaviour
 {
     public GameObject explosion;
     public GameObject PlayerExplosion;
 
     private void OnTriggerEnter(Collider other)
     {
         if (other.tag == "Boundary") 
         {
             return;
         }
         Instantiate(explosion, transform.position, transform.rotation);
         if (other.tag == "Player") 
         {
             Instantiate(PlayerExplosion, other.transform.position, other.transform.rotation);
         }
         Destroy(other.gameObject);
         Destroy(gameObject);
     }
 }