Get third Person Character on blueprint trigger

Hello everyone, I allow myself to present my problem, for several days I am looking for a solution. I said that I did a lot of research on the Web before finishing here I make a little game on Unreal Engine while blueprint. I already have a map with the horizontal movement management of my ball. This ball, as I understand it a Third Person Character: Here are blueprint:

It can be seen that I apply a change of X, Y, Z coordinates to my Actor “ball”, and everything works perfectly. Where it gets complicated is when I want to add a trigger on my map like this:


This trigger will allow me to make some movement on my Actor “ball” when it touches the trigger. Here is the blueprint of the trigger I made:

Normally the change of coordinates X, Y, Z should apply to the Actor “Ball” … instead, here is the error message that I get when starting the simulation: PICTURE 4
I guess I do not have access to the Actor “ball” in the trigger’s blueprint. But I tried a lot of things, but I did not find the way to recover my “ball” to be able to apply to him are movement at the launch of this trigger … Thank you in advance for your time and help, Have a good day.