Respawn Error

Hello people! I am having a slight problem with my game, at the moment I have enemies that spawn and move towards the player. Once the player dies, I have coded them to stop moving towards the player and to stop spawning (or so I think I have)

The problem is when I click the "Reload" button that I have implemented, which basically just loads the scene back up "Application.LoadLevel"

I get this error, "NullReferenceException: Object reference not set to an instance of an object EnemyMove.Update () (at Assets/Scripts/EnemyMove.cs:14)"

The game runs fine though even after the error, any ideas on what I am doing wrong?

Here is the code for that particular script...

 using UnityEngine;
 using System.Collections;
 
 public class EnemyMove : MonoBehaviour {
 
     float speed = 3.0f; // move speed
     public static float score = 0.0f;
     public GameObject Explosion;
 
 
     void Update(){
         if (GameObject.FindGameObjectsWithTag ("Player") != null && PointAndFire.Hit >= 1) {
                         GameObject target = GameObject.FindGameObjectWithTag ("Player");
                         transform.position = Vector3.MoveTowards (transform.position, target.transform.position, speed * Time.deltaTime);

                 } else if (GameObject.FindGameObjectsWithTag ("Player") == null) {
                 }
         {
         }
     }
     void OnCollisionEnter (Collision col)
     {
         if(col.gameObject.name == "bullet 2(Clone)")
         {
             Destroy(col.gameObject);
     
             score += 1.0f;
             Debug.Log(score);
             Instantiate (Explosion,transform.position, transform.rotation);
         }
 }
     void OnCollisionPlayer (Collision col)
     {
         if(col.gameObject.tag == "Player")
         {
             Destroy(gameObject);
         }
     }
 }

I think the error lies in void Update