How to resolve NullReferenceException error across two scripts?

Questions & Answers
1

This is a follow-up to a previous post I made regarding one script triggering another script. I have been able to trigger a collision, but upon the collision being triggered, the function in the second script isn’t being called, and instead I receive this error:

NullReferenceException: Object reference not set to an instance of an object
Reflection_Trigger.OnTriggerEnter (UnityEngine.Collider collision) (at Assets/Reflection_Trigger.cs:18)

Here is the first script, entitled Reflection_Trigger, which triggers the second script upon detection of a collision:

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

public class Reflection_Trigger : MonoBehaviour
{

    public Reflective_Door reflectiveDoor;


    void OnTriggerEnter(Collider collision)
    {

        if (collision.transform.gameObject.name == "PlayerCapsule")
        {
            Debug.Log("Collided!");
            reflectiveDoor.CloseDoor();
            Debug.Log("Function Called!");
        }
    }
}

Here is the second script, entitled Reflective_Door, which should be called by the first script upon collision detection, and move an assigned object to another location:

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

public class Reflective_Door : MonoBehaviour
{
    public void CloseDoor()
    {
        Debug.Log("Door Closed!");
        transform.position = new Vector3(-9.06f, 2.56f, 74.87f);
    }
}

I want to know how I can resolve the NullReferenceException error and successfully trigger one script using another. I am new to Unity so any help on this would be greatly appreciated. Thank you.

2

the reflectiveDoor is null, so no one can Close it

You should follow video tutorials before DIY sth.