Question Object reference unassigning itself at runtime

I'm trying to reference the grid object which contains a script that has my inventorygrid class. I'm referencing from another script attached to the ui camera.

Its assigned like this:


I'm just trying to reference it like this:

Code (CSharp):

1. public class InventoryController : MonoBehaviour
2. {
3.     [SerializeField] private InventoryGrid selectedInventoryGrid;
4.  
5.     private void Update()
6.     {
7.         if (selectedInventoryGrid = null)
8.         {
9.             Debug.Log("InventoryGrid IS null.");
10.             return;
11.         }
12.  
13.  
14.         selectedInventoryGrid.GetTileGridPosition(Input.mousePosition);
15.     }
16. }

However, when trying to run the referenced class and method, I get "Object reference not set to an instance of an object.". I've noticed that the "Selected Inventory Grid" that I've assigned just unassigns itself when I run the game.

 

In C# = is used to assign things and == is used to compare.

Here you are assigning it to null.

 

selectedInventoryGrid = null

should be

selectedInventoryGrid == null