WasCollected()/WasCollected_Implementation()

I am practicing Unreal by watching through one of Unreal tutorials (posted on youtube).

I am facing an issue (FYI, my Unreal version is 4.18).
This is about when the character destroys the battery, the arc should be spawning.
I saw Blueprint calls the event of “WasCollected”, but during the play, it doesn’t activate the event of the “WasCollected” even if the battery is collected by pressing “c” button.
Visual studio complains WasCollected() is not a defined function, but there’s virtual void WasCollected_Implementation(); under UFUNCTION(BlueprintNativeEvent)

Do you know if there’s something changed somewhere between your engine version (at the time you recorded, I believe it.s 4.9) and 4.18?

I never program in blueprints so I’m not 100% sure, but it really looks like you might have created an infinite loop here (I highlighted it in red).