Why am I getting a NullReferenceException while trying to set a Sprite? (C#)

I created a tool for automatically generating a group of hexes. It can successfully create, name, and place the GameObjects in the right place. However, when I tried to make it give the objects a default sprite, I kept getting a null reference error on line 17 which just says HexImage =. If I get rid of this part of the code, the hex objects each get an empty Sprite Renderer. Is there a way to assign he default sprite other than this, or is there some way I can resolve this issue?

Here is the error I am getting:

 NullReferenceException: Object reference not set to an instance of an object
 HexGenerator.Create () (at Assets/Editor/HexGenerator.cs:17)

This is the code I am using:

 using UnityEngine;
 using UnityEditor;
 using System.Collections;
 
 public class HexGenerator 
 {
     [MenuItem("Hex Board/Generate Tiles")]
     static void Create()
     {
         int y = 6;
         int x = 6;
         float Xdist = 1.328f; //The x distance between adjacent tiles
         float Ydist = 1.016f; //The y distance between adjecent tiles
         //GameObject Container = new GameObject("Hexes");
         GameObject HexBlueprint;
         Sprite HexImage = new Sprite();
         HexImage = 
             Sprite.Create(Resources.Load<Texture2D>("Assets/Base Hex.png"),
             new Rect(0, 0, Resources.Load<Texture2D>("Assets/Base Hex.png").width, Resources.Load<Texture2D>("Assets/Base Hex.png").height),
             new Vector2(0.5f, 0.5f));
 
         for (int i = 0; i < y; i++)
         {
             for (int j = 0; j < x; j++)
             {
                 if (i % 2 == 0)
                 {
                     HexBlueprint = new GameObject("Hex " + j + "," + i);
                     HexBlueprint.transform.position = new Vector3(j * Xdist, i * Ydist);
 
                     SpriteRenderer renderer = HexBlueprint.AddComponent<SpriteRenderer>();
                     renderer.sprite = HexImage;
                 }
                 else
                 {
                     HexBlueprint = new GameObject("Hex " + j + "," + i);
                     HexBlueprint.transform.position = new Vector3(j * Xdist + Xdist / 2, i * Ydist);
 
                     SpriteRenderer renderer = HexBlueprint.AddComponent<SpriteRenderer>();
                     renderer.sprite = HexImage;
                 }
             }
         }
     }
 }