Accessed None trying to Read Property

I am not sure if it an order problem. Besides that, I cannot understand why Inventory WindowRef is Accessing none. For context, this is my Inventory Component’s Event Graph. The interface event is for the component to know what item was picked up. Also, the Search Inventory For Stack, Then Add function is a self-made function within the Widget blueprint “Inventory Window”. It would be greatly appreciated if anyone has a solution or alternative to this problem!