Why are there no enemies spawning in the 2d roguelike tutorial I am doing?

I am on the 5th lesson of the 2d Roguelike tutorial and I am having the issue of all of my other game objects instantiate correctly, yet the enemies do not. It looks like the code is correct. I have retyped it several times. If I drag a new prefab directly into the Scene the sprite shows up just fine. Any ideas as to why the sprites are not showing up when Board Manager tries to instantiate them? I included the code for reference.

using UnityEngine;
using System;
using System.Collections.Generic;
using Random = UnityEngine.Random;


public class BoardManager : MonoBehaviour {

    [Serializable]
    public class Count
    {
        public int minimum;
        public int maximum;

        public Count(int min, int max)
        {
            minimum = min;
            maximum = max;
        }
    }

    public int columns = 8;
    public int rows = 8;
    public Count wallCount = new Count(5, 9);
    public Count foodCount = new Count(1, 5);
    public GameObject exit;
    public GameObject[] floorTiles;
    public GameObject[] wallTiles;
    public GameObject[] foodTiles;
    public GameObject[] enemyTiles;
    public GameObject[] outerWallTiles;

    private Transform boardHolder;
    private List<Vector3> gridPositions = new List<Vector3>();

    void InitaliseList()
    {
        gridPositions.Clear();

        for (int x = 1; x < columns - 1; x++)
        {
            for (int y = 1; y < rows - 1; y++)
            {
                gridPositions.Add(new Vector3(x, y, 0f));
            }
        }
    }

    void BoardSetup ()
    {
        boardHolder = new GameObject("Board").transform;

        for (int x = -1; x < columns + 1; x++)
        {
            for (int y = -1; y < rows + 1; y++)
            {
                GameObject toInstantiate = floorTiles[Random.Range(0, floorTiles.Length)];
                if (x == -1 || x == columns || y == -1 || y == rows)
                    toInstantiate = outerWallTiles[Random.Range(0, outerWallTiles.Length)];

                GameObject instance = Instantiate(toInstantiate, new Vector3(x, y, 0f), Quaternion.identity) as GameObject;

                instance.transform.SetParent(boardHolder);
            }
        }
    }

    Vector3 RandomPosition()
    {
        int randomIndex = Random.Range(0, gridPositions.Count);
        Vector3 randomPosition = gridPositions[randomIndex];
        gridPositions.RemoveAt(randomIndex);
        return randomPosition;

    }

    void LayoutObjectAtRandom(GameObject[] tileArray, int minimum, int maximum)
    {
        int objectCount = Random.Range(minimum, maximum + 1);

        for (int i = 0; i < objectCount; i++)
        {
            Vector3 randomPosition = RandomPosition();
            GameObject tileChoice = tileArray[Random.Range(0, tileArray.Length)];
            Instantiate(tileChoice, randomPosition, Quaternion.identity);

        }
    }

	public void SetupScene (int level)
    {
        BoardSetup();
        InitaliseList();
        LayoutObjectAtRandom(wallTiles, wallCount.minimum, wallCount.maximum);
        LayoutObjectAtRandom(foodTiles, foodCount.minimum, foodCount.maximum);
        int enemyCount = (int)Mathf.Log (level, 2f);
        LayoutObjectAtRandom(enemyTiles, enemyCount, enemyCount);
        Instantiate(exit, new Vector3(columns - 1, rows - 1, 0F), Quaternion.identity);


    }
}

Never mind, I figured out that the sorting layer was set to Default instead of Units and that was causing the issue.