Me Blueprint Character Doesn't Appear

I am on this step of the tutorial:

And when I 've done everything , I hit Play and nothing happens. (well , the side scroller falls in the ground , but thats it)

There is a note at almost the end of the videos wich says: “If the instance of the MyCharacter blueprint doesn’t show, you will need to check the GameMode Override Setting in the Game Mode section of the World Settings, which can be located under Settings > World Settings”

My World Setting are these:

I Guess they are ok.

Could anyone help ?

Yeah , Player’s Start Location is: x=350.0 y=0.0 z=220.0

y is 0 since is a 2D Game

the side scroller falls in the ground

That sounds like your character does get spawned but is falling through the floor. Is your PlayerStart object above a valid (collidable) surface?

Well, I finally find the answer in a comment on Youtube discussion

I hit Play and Simulate it but the character appears only when I hit Possess.

Don’t know why , but it’s a fix!