How to fix "Access none trying to read property" Error | how to set Object Reference

Hey guys I’m trying to learn UE5 and ran into problem. So for context, What I want to do is simply keep a count of how many times the moving tile hits a static tile and display it on a widget.

https://blueprintue.com/blueprint/gp7ro3ht/

Now, I do have a superficial understanding of why it failed, as I did not 'initialise the object reference

Unlike the mobile_tile, which I cast to and the promote to a variable in the component overlap event

https://freeimage.host/i/image.BIjuPbs

The gamemode_ref is causing the error

And that is my question. How do I set the object when there isn’t a direct situation to do so (for example overlap event )?

Where is gamemode_ref initialized? Asking since don’t see it in the screenshots.

Hey I have added linkk to the whole bluprint but here is the screenshot