When I hover over the itemName of this code: "inventory[i].itemName", it says "Unresolved member 'itemName'" in the tooltip.

The biggest issue is that when I press period after [i], AutoComplete/IntelliSense still shows the old variables I originally made my InventoryItem class with (before itemName was there). It won't update to show itemName/itemObject/itemTex.

But the full code does compile and work.

public InventoryItem[] inventory;

[System.Serializable]
public class InventoryItem
{
    public string itemName;
    public GameObject itemObject;
    public Texture2D itemTex;
}

public void AddItem(InventoryItem item)
{
    for(int i = 0; i < inventory.Length; i++) 
    {
       if (inventory[i].itemName == null && inventory[i].itemObject == null && inventory[i].itemTex == null)
       {
            inventory[i] = item;
         print("ADDED - " + inventory[i].itemName + " - to slot " + i);
         return;
       }
    }   
    print("Inventory full and i = " + inventory.Length);
}