Combine Integer that I create for a button click from a button in multiple widgets

Hello,
I need help with one issue that I’m having. It prevents the game from packaging. I created item widget that has a button which adds this item to the inventory and displays items count in the inventory icon which becomes visible after 1st item is added.

There are about 100 of these items in the scene and they are pretty much their own widgets that feed “Add to Inventory” button click count to the Inventory icon widget via Custom event with Integer added.

Problem is when the click integer come through the custom event I then have to combine all of into one variable. I used “+ Add” node but there is a limit to how many pins I can add to this node, so then I just duplicated and added from the first “+” node to the second one and so forth.
It works in the editor but when I compile it shows problem that it can’t find “inter + integer” connection and can’t expand pins. I don’t understand what’s going on, theoretically it should work but there is a problem while packaging the game.

There should be a solution.