How to fix this...

When i equip a item from my inventory to equippment that is going ok but back nothing happens and my equippment tab disapears and i cant do anything (btw tut from JesseEtzler0)
my error is : NullReferenceException: Object reference not set to an instance of an object
my code is :

import System.Collections.Generic;

//Holding all of our items.
var items : Item[];

//Inventory
var MainInventory : List.<Item> = new List.<Item>();

//Equip Menu [0 = helm, 1 = shoulders, 2 = gloves, 3 = pants, 4 = boots, 5 = ring, 6 = neckless]
var EquipMenu : Item[];

var Power : int = 0;

function Start ()
{
    MainInventory.Add(items[0]);
    MainInventory.Add(items[0]);
    MainInventory.Add(items[1]);
    EquipMenu[0] = null;
}

function OnGUI ()
{
    for(var x =0; x < MainInventory.Count; x++)
    {
        if(GUI.Button(Rect(Screen.width / 2, Screen.height / 2 + (20 * x), 100, 20), GUIContent ( MainInventory[x].Name, "Stamina! " + MainInventory[x].Stamina)))
        {
            if(MainInventory[x].itemType == MainInventory[x].itemType.helm)
            {
                if(EquipMenu[0] != null && EquipMenu[0].equiped == true)
                {
                    MainInventory.Add(EquipMenu[0]);
                }
                EquipMenu[0] = null;
                EquipMenu[0] = MainInventory[x];
                Power += EquipMenu[0].Power;
                MainInventory.RemoveAt(x);
                Debug.Log(Power);
               
            }
            else if(MainInventory[x].itemType == MainInventory[x].itemType.shoulders)
            {
                EquipMenu[1] = MainInventory[x];
                MainInventory.RemoveAt(x);
            }
          
        }
    }
    for(var y = 0; y < EquipMenu.length; y++)
    {
        if(EquipMenu[y] != null)
        {
            if(GUI.Button(Rect(Screen.width / 2 - 150, Screen.height / 2 + (20 * y), 100, 20), "" + EquipMenu[y].Name))
            {
                if(EquipMenu[y] != null)
                {
                    MainInventory.Add(EquipMenu[y]);
                    Power -= EquipMenu[y].Power;
                    EquipMenu = null;
                    Debug.Log(Power);
                }
            }
        }
    }
}

Please, don’t double-post on the forum, man. I replied to your last post about this same issue. If you don’t know how to debug a NullReferenceException, there is little that the community can do for you. NullReferences are VERY VERY broad errors. Use the Debug Console, double click on the error, and copy/pase the line of code that it takes you to.