NullRefferenceException at animation

So... I have a NRE (NullRefferenceException ) into my game... I know how to normally fix a NRE but now I don't know how to face with this one. Before showing to you my code I will say what kind of problem I have. When I pass from scene 1 ---> 2 everything is good with my game. When I pass from scene 2 back to 1 after I take some damage my game work fine yea my life system. But when I pass again from scene 1 --->2 I take this error NullReferenceException: Object reference not set to an instance of an object LifeControler.UpdateHP (Int32 life, System.Boolean& gameOver) (at Assets/Scripts/LifeControler.cs:34) PlayerControlle.Start () (at Assets/Scripts/PlayerControlle.cs:42) This blow my mind because it happen when I pass from scene to scene. Any help? Scripts bellow:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class LifeControler : MonoBehaviour {
 
     private Animator animator;
     private Vector3 position;
 
     void Awake()
     {
         position = transform.position;
     }
 
     void LateUpdate()
     {
         transform.position = position;
     }
     void Start()
     {
         animator = GetComponent<Animator> ();
         if (animator == null)
             Debug.Log ("Animator in LifeController is missing");
         
     }
 
     public bool UpdateHP(int life, out bool gameOver)
     {
         gameOver = false;
         switch (life) {
         case 4:
             return gameOver = false;
         case 3:
             animator.SetTrigger ("3Life");
             return gameOver = false;
         case 2:
             animator.SetTrigger ("2Life");
             return gameOver = false;
         case 1:
             animator.SetTrigger ("1Life");
             return gameOver = false;
         case 0:
             animator.SetTrigger ("Dead");
             return gameOver = true;
         default:
             Debug.Log ("LifeController error");
             return gameOver = true;
 
         }
     }
 }

 




 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.SceneManagement;
 
 public class PlayerControlle : MonoBehaviour {
 
     public int speed;
 
     static public int gold;
     static public int currentLife;
     bool gameOver = false;
 
     public GameObject bolt;
     public GameObject boltUp;
     public GameObject boltSpawnRight;
     public GameObject boltSpawnLeft;
     public GameObject boltSpawnBack;
     public GameObject boltSpawnForward;
     public Text gameOverText;
 
     private float vertical;
     private float horizontal;
     private bool stopInput = false;
 
     private Rigidbody2D rb;
     private Animator animator;
     private LifeControler life;
 
 
 
     void Start () {
         rb = GetComponent<Rigidbody2D> ();
         animator = GetComponent<Animator> ();
         life = GetComponentInChildren<LifeControler> ();
         if (GlobalControl.Instance != null)
             currentLife = GlobalControl.Instance.CurrentLife;
         else if (GlobalControl.Instance == null)
             Debug.Log ("GlobalControl is null");
         life.UpdateHP (currentLife, out gameOver);
         if (gameOverText != null)
             gameOverText.text = " ";
     }
     private void OnDisable()
     {
         GlobalControl.Instance.CurrentLife = currentLife;
     }
     void Update () {
 
         if (horizontal > 0) 
         {
             animator.SetTrigger ("playerMoveRight");
         
             if (Input.GetKeyDown (KeyCode.K))
                 Instantiate (bolt, boltSpawnRight.transform.position, Quaternion.Euler(new Vector3(0, 0, 0)));
         }
         if (horizontal < 0)
         {
             
             animator.SetTrigger ("playerMoveLeft");
             if (Input.GetKeyDown (KeyCode.K))
                 Instantiate (bolt, boltSpawnLeft.transform.position,  Quaternion.Euler(new Vector3(0, 180, 0)));
             
         }
         if (vertical > 0) 
         {
             
             animator.SetTrigger ("playerMoveBack");
             if (Input.GetKeyDown (KeyCode.K))
                 Instantiate (boltUp, boltSpawnBack.transform.position,  Quaternion.Euler(new Vector3(0, 0, 0)));
             
         }
         if (vertical < 0) 
         {
             animator.SetTrigger ("playerMoveForward");
             if (Input.GetKeyDown (KeyCode.K))
                 Instantiate (boltUp, boltSpawnForward.transform.position,  Quaternion.Euler(new Vector3(180, 0, 0)));
             
         }
         rb.velocity = new Vector2 (horizontal * speed, vertical * speed);
 
         if (vertical == 0 && horizontal == 0) 
         {
             animator.SetTrigger ("playerIdle");
             if (Input.GetKeyDown (KeyCode.K))
                 Instantiate (boltUp, boltSpawnForward.transform.position,  Quaternion.Euler(new Vector3(180, 0, 0)));
         }
 
     }
     void FixedUpdate()
     {
         if(!stopInput)
             horizontal = Input.GetAxis ("Horizontal");
         if(!stopInput)
         vertical = Input.GetAxis ("Vertical");
         rb.velocity = new Vector2 (horizontal * speed, vertical * speed);
     }
 
 
     IEnumerator TakeDamage(int damageValue)
     {
         currentLife = currentLife - damageValue;
         life.UpdateHP (currentLife, out gameOver);
         if (gameOver) {
             stopInput = true;
             gameOverText.text = "Game Over" +
                 "\n Wait 5 seconds";
             yield return new WaitForSeconds (5);
             SceneManager.LoadScene (0);
         }
     }
     void OnTriggerEnter2D(Collider2D other)
     {
         if (other.gameObject.CompareTag ("Bolt")) {
             StartCoroutine (TakeDamage (1));
             Destroy (other.gameObject);
 
         }
     }
 }

I hope you can help me and thanks a lot.