The object of type "GameObject" has been destroyed but you are still trying to access it.

What causes this problem?
Im trying to make a coop multiplayer game against ai so it has 2 players which might cause the error but im a begginer so i dont really know.
Here is my code if it helps:

Code (CSharp):

1. using UnityEngine;
2. public class followplayer : MonoBehaviour
3. {
4.     public GameObject Player;
5.     public GameObject Player2;
6.     public GameObject enemy;
7.     public float maxdist = 30;
8.     public float movementSpeed = 10;
9.     void Update()
10.     {
11.         float distP1 = Vector3.Distance(Player.transform.position, enemy.transform.position);
12.         float distP2 = Vector3.Distance(Player2.transform.position, enemy.transform.position);
13.         if(distP1 <= maxdist)
14.         {
15.             if(distP2 <= distP1)
16.             {
17.                 transform.LookAt(Player2.transform);
18.                 transform.position += transform.forward * movementSpeed * Time.deltaTime;
19.             }
20.             if (distP1 <= distP2)
21.             {
22.                 transform.LookAt(Player.transform);
23.                 transform.position += transform.forward * movementSpeed * Time.deltaTime;
24.             }
25.         }
26.         if (distP2 <= maxdist)
27.         {
28.             if (distP2 <= distP1)
29.             {
30.                 transform.LookAt(Player2.transform);
31.                 transform.position += transform.forward * movementSpeed * Time.deltaTime;
32.             }
33.             if (distP1 <= distP2)
34.             {
35.                 transform.LookAt(Player.transform);
36.                 transform.position += transform.forward * movementSpeed * Time.deltaTime;
37.             }
38.         }
39.     }
40. }

 

One your three gameobjects is being destroyed in another script and you don't check for null.

 

what do you mean destroyed?

 

GameObject.Destroy, or Object.Destroy has been called on it. Either explicitly or implicitly by destroying a parent GameObject or unloading the scene it's root GameObject is in.