Как исправить ошибку NullReferenceException: Object reference not set to an instance of an object?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class user : MonoBehaviour
{
    public float Distens = 0f;
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.E))
        {
            Ray ray=new Ray (transform.position, transform.forward);
            RaycastHit hit;
            if(Physics.Raycast(ray, out hit, Distens))
            {
                if (hit.collider.CompareTag("door"))
                {
                    hit.collider.transform.parent.GetComponent<DoorScript>().count_v();
                }
            }
        }
    }
}

using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;

public class DoorScript : MonoBehaviour
{
    private int count = 3;

    public void count_v()
    {
        count--;
        print(count);
        count--;
    }
}