Fade in/Out in C++

Guys Im almost done to fix this. Sorry for not being able to write what I want to achieve.
I want to create a Fade effect whenever the player dies, so I created the MatineeActor and I want it to be played when the character dies. So I did this.

#include "Matinee/MatineeActor.h"

This is in the .cpp and with this, you can access all funcs and variables of the class AMatineeActor and now I can create objects with it, then I added:

UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Death FX")
   class AMatineeActor* DeathFader;

So now with this I can choose the MatineeActor I want to play. In the defaults tab on my Character BP, theres a menu that displays the available MatineeActors, but when I try to choose the specific MatineeActor, I just can’t, I click and click it and the dropbox keeps displaying “None” like if something is wrong. Im sure im missing something, ¿Can you please help?

BTW, Im using UE4.6