Destroying childs and Instantiate [C#]

Hey everybody ! I'm making a RPG and i have a problem with my inventory : When i open the inventory menu (there is two sub_menu : items and resssources, and a window where we can see items and ressources properties), the item menu is open with all items and all work. when i go to the ressources menu a method delete items that's for again. The ressource menu work too and when i go to the item menu, the same method delete ressources.

But now, when we click on a item to see his properties, this error appear : MissingReferenceException: The object of type 'GameObject' has been destroyed but you are still trying to access it.

I check the instantiated items, nothing is missing...

These are the scripts :

Instantiating Items (it is the same for ressources):

  GameObject defaultItem = new GameObject();
                     i++;
                     defaultItem = (GameObject)Instantiate(emptyItem, new Vector3(0, 0, 0), Quaternion.identity);
 
                     BaseItems it = defaultItem.AddComponent<BaseItems>() as BaseItems;
                     it.AddItem(bI);
 
                     defaultItem.transform.parent = ITEM_Slots[i].transform;
                     defaultItem.transform.localPosition = new Vector3(0, 1, 0);
 
                     ITEM_Slots[i].GetComponent<Button>().onClick.AddListener(() => DisplayInventoryInfos(defaultItem.GetComponent<BaseItems>(), null));
                     defaultItem.GetComponent<Image>().sprite = defaultItem.GetComponent<BaseItems>().ITEM_Image;
                     defaultItem.GetComponent<RectTransform>().localPosition = new Vector3(0, 0, 0);
                     defaultItem.GetComponent<RectTransform>().sizeDelta = new Vector2(16,16);
 
 
                     inventoryItemChildsList.Add(defaultItem);
                     defaultItem.name = defaultItem.GetComponent<BaseItems>().ITEM_Name;

the scipt to delete items and ressources :

     public void DestroyInventoryChild(List<GameObject> childs)
     {
         foreach (GameObject child in childs)
         {
             Destroy(child);
         }
     }

And the script to show properties :

 public void DisplayInventoryInfos(BaseItems bI, BaseRessources bR)
 {
     if(bI != null)
     {
         INFO_Name.GetComponent<Text>().text = bI.ITEM_Name;
         INFO_Image.GetComponent<Image>().sprite = bI.ITEM_Image;
         INFO_Level.GetComponent<Text>().text = bI.ITEM_Level.ToString();

         if(bI.ITEM_Type == ITEM_TYPE.ARMOR)
         {
             INFO_Type.GetComponent<Text>().text = bI.ARMOR_Type.ToString();
         }
         else if(bI.ITEM_Type == ITEM_TYPE.WEAPON)
         {
             INFO_Type.GetComponent<Text>().text = bI.WEAPON_Type.ToString();
         }

         int j = 0;
         foreach(ItemStat iS in bI.ITEM_STATS)
         {
             INFO_Effects[j].GetComponent<Text>().text = iS.STAT_Affected.ToString() + " " + iS.value.ToString(); 
             j++;
         }

     }
     else if(bR != null)
     {
         INFO_Name.GetComponent<Text>().text = bR.RESSOURCE_Name;
         INFO_Image.GetComponent<Image>().sprite = bR.RESSOURCE_Image;
         INFO_Level.GetComponent<Text>().text = bR.RESSOURCE_Level.ToString();
         INFO_Type.GetComponent<Text>().text = bR.RESSOURCE.ToString();
         INFO_Effects[0].GetComponent<Text>().text = "Ressource.";
     }
 }

Thank you !

Bye, xyHeat