Strange Problem: NullReferenceException

Here is what it says

“NullReferenceException: Object reference not set to an instance of an object at ItemCounter.Update () [0x0001c]
in C:\Users\Documents\3dPlatformer\Assets\C# Scripts\ItemCounter.cs:16
(Filename: C Line: 0)”

NullReferenceException: Object reference not set to an instance of an object

I know what this means, I have the game objects set in the inspector.

This error only occurs in the Built Standalone version.

There is no error when in the Unity3d Editor Player.

If anyone can help with this that would be amazing! Thanks

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

public class ItemCounter : MonoBehaviour {

	private bool finished = false;
	public int maxItems;

	public GameObject enableThisObject;
	public GameObject disableThisObject;

	public int currentItems = 0;
	

	void Update(){
		if(currentItems >= maxItems && finished == false){
			enableThisObject.SetActive(true);
			disableThisObject.SetActive(false);
			finished = true;
		}
	}

	void OnTriggerEnter(Collider items){
		if(items.gameObject.name == "item"){
			currentItems += 1;
		}

	}

	void OnTriggerExit(Collider leave){
		if (leave.gameObject.name == "item") {
			currentItems -= 1;
		}
	}

}

if(currentItems >= maxItems && finished == false){

		***if(enableThisObject != null && enableThisObject != null)***
		{
     		enableThisObject.SetActive(true);
     		enableThisObject.SetActive(false);
     		finished = true;
		}
   }

try with adding one more condition for checking null. like above

I think I found a solution - do not use “incremental GC”