[Solved] Null Reference Exception on a text variable

Hi guys

I'm working on a script for a wave spawner when i lauch the game the script start i get this error :

NullReferenceException: Object reference not set to an instance of an object ZombieGameMode.Update () (at Assets/Mes Asset/Script/JeuInfo/ZombieGameMode.js:50)

I've checked in the Inspector and both of the variable are set i've try a lot of thing and it doesn't fix it (Sorry for my english i'm frebch btw)

Here is my script :

 #pragma strict
 import UnityEngine.UI;
 
 var Second : int  = 00;
 var Minute : int = 00;
 var Wave : int = 00;
 var WaveTimer : int = 00 ;
 var boucle : boolean = false;
 var TimerUI : Text ;
 var WaveUI : Text ;
 var ennemy1 : GameObject;
 
 
 private var spawnSpawner : int ;
 private var SpawnNumber : int ;
 var Spawn : int ;
 var SpawnCount : int = 10 ; 
 public var AllSpawner : GameObject[];
 
 
 function Start () {
     AllSpawner = GameObject.FindGameObjectsWithTag("Spawner"); ;
     SpawnNumber = AllSpawner.length ;
 }
 
 
 function Update () {
 
 
     //Veriffier toute les frame les seconde 
     if (boucle == false){
         Secondcount();
         boucle= true ;
     }
 
     if(Second == 60){
         Minute = Minute + 1;
         Second = 0 ;
     }
 
     if(Minute == WaveTimer ){
         WaveTimer = WaveTimer +1;
         Wave = Wave + 1 ;
         SpawnCount = SpawnCount*1.5 ;
         Spawns();
     }
 
 
     //Ubdate le time
     TimerUI.text= Minute+" : "+Second;
     //Ubdate les wave 
     WaveUI.text = "Wave : "+ Wave ;
 
 
 }
 
      
            
    
 
 
 function Spawns(){
     spawnSpawner = SpawnCount/SpawnNumber ;
     for(var i=0; i < spawnSpawner;i++){
     for(var Place : GameObject in AllSpawner){
         yield WaitForSeconds(1);
         var position = Place.transform.position ;
         Instantiate (ennemy1,position,transform.rotation) ;
     }
         
     }
 }
 
 
 //Ajouter une seconde toute les seconde
 function Secondcount(){
     Second = Second + 1 ;
     yield WaitForSeconds(2);
     boucle = false ;
 }