Array is out of range?

That kind of error comes up when I try to acces function Activation from other script. My script is as follows:

 private var mysteryBox        : GameObject[]            = null;
 var numbersToCreate         : int                 = 0;
 
 function Start () 
 {
         mysteryBox = new GameObject [numbersToCreate];    
     InstantiateMysteryBox();    
 }
 
 function Activation()
 {
     for(var i : int  = 0; i < numbersToCreate; i++)
         {
             if(mysteryBox[i].active == false)
             {
                 mysteryBox[i].SetActiveRecursively(true);
                 mysteryBox[i].GetComponent(scriptMysteryBox).Activate();
                 return;
             }
         }
 }
 
 function InstantiateMysteryBox()
 {
     for(var i : int = 0; i < numbersToCreate; i++)
     {
         mysteryBox[i] = Instantiate(Resources.Load("Prefabs/prefabMysteryBox"));
         mysteryBox[i].SetActiveRecursively(false);
     }        
 }