Minesweeper UI Issue

I'm making a minesweeper game and I am using the code below. from two separate classes.

 using System.Collections;
 using UnityEngine;
 
 public class Element : MonoBehaviour
 {
     //bool used to identify whether there is a mine or not hence True/False
     public bool mine; 
 
     public Sprite[] emptyTextures; //array for sprites
     public Sprite mineTexture;
 
     private void Start()
     {//Randomly decide whether it is a mine or is not
         mine = Random.value < 0.15;
 
         //converts from float to int
         int x = (int)transform.position.x;
         int y = (int)transform.position.y;
         NewGrid.elements[x, y] = this;   
 
       
 
 
 
     }
 
     public void loadTextures (int count) //counts the number of surrounding mines 
     {
         //will check if element is a mine or not 
 
         //if yes it loads the texture 
         if(mine) 
             GetComponent<SpriteRenderer>().sprite = mineTexture; 
         //if not it loads a number from the empty textures array
         else
             GetComponent<SpriteRenderer>().sprite = emptyTextures[count];
             
         
     }
 
     public bool isCovered () {  // checks if sprite is covered
 
         return GetComponent<SpriteRenderer>().sprite.texture.name == "Default";
     }
 
     void check (){ //check if player has clicked sprite and check if clicked is mine
 
         //if it is a mine
         if (mine) {
             //uncover all mines 
             NewGrid.uncoverMines();
 
             //notify user that they have lost 
             print("You Lose...LOSER");
         } else {
             // show adjacent mine number
             int x = (int)transform.position.x;
             int y = (int)transform.position.y;
             loadTextures(Grid.adjacentMines(x, y));
             // uncover area without mines
             NewGrid.FFuncover(x, y, new bool[NewGrid.w, NewGrid.h]);
 
             // find out if the game was won now
             if (NewGrid.isFinished())
                 print("you win");
         }
     } 
 }
 
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class NewGrid
 {
 
     public static int w = 10; //Width
     public static int h = 13; //Height
 
     //creates 2D element array that takes in the width and height variables
     public static Element[,] elements = new Element[w, h];
 
 
     //function to uncover mines
     public static void uncoverMines()
     {
         foreach (Element elem in elements)
             if (elem.mine)
                 elem.loadTextures(0);
     }
 
     // Find out if a mine is at the coordinates
     public static bool mineAt(int x, int y)
     {
         // If coordinates in range check for mine.
         if (x >= 0 && y >= 0 && x < w && y < h)
             return elements[x, y].mine;
         return false;
     }
 
     // Count adjacent mines for an element
     public static int adjacentMines(int x, int y)
     {
         int count = 0;
 
         if (mineAt(x, y + 1)) ++count; // top
         if (mineAt(x + 1, y + 1)) ++count; // top-right
         if (mineAt(x + 1, y)) ++count; // right
         if (mineAt(x + 1, y - 1)) ++count; // bottom-right
         if (mineAt(x, y - 1)) ++count; // bottom
         if (mineAt(x - 1, y - 1)) ++count; // bottom-left
         if (mineAt(x - 1, y)) ++count; // left
         if (mineAt(x - 1, y + 1)) ++count; // top-left
 
         return count;
     }
 
     // Flood Fill empty elements
     public static void FFuncover(int x, int y, bool[,] visited)
     {
         // Coordinates in Range?
         if (x >= 0 && y >= 0 && x < w && y < h)
         {
             // visited already?
             if (visited[x, y])
                 return;
 
             // uncover element
             elements[x, y].loadTextures(adjacentMines(x, y));
 
             // close to a mine? then no more work needed here
             if (adjacentMines(x, y) > 0)
                 return;
 
             // set visited flag
             visited[x, y] = true;
 
             // recursion
             FFuncover(x - 1, y, visited);
             FFuncover(x + 1, y, visited);
             FFuncover(x, y - 1, visited);
             FFuncover(x, y + 1, visited);
         }
 
     }
 
     public static bool isFinished()
     {
         // Try to find a covered element that is no mine
         foreach (Element elem in elements)
             if (elem.isCovered() && !elem.mine)
                 return false;
         // There are none => all are mines => game won.
         return true;
     }
 }
 
 

My issue is that when I run the build on visual studio code it compiles perfectly but when I attempt to run on game mode I am hit with several errors all saying the same thing. The error is: NullReferenceException: a null value was found where an object instance was required

it keeps pointing to line 19 which has this code NewGrid.elements[x, y] = this;

I didn't initiate the array to a fixed value I just initiated a 2D array so I don't understand why I am getting this error?