Cast to dose not work

Player Score seems to be of type HUD, so you would need the reference of HUD, which is under Player Controller. You were pretty close actually. You just needed to Get HUD from Player Controller: http://puu.sh/oBvY6/6049fc3d5e.png

it dose not work why

Is your Player_Score_HUD actually a HUD class or UMG Widget?

UMG CLASS

You’re killing me smalls.

To create UMG widgets and have them appear follow this [UMG Guide][1]
OnBeginOverlap: Create Widget, Set It, Add to Viewport.

On EndOverLap: you can Remove From Parent.

To Cast to UMG Widgets: Super Lazy Way:

http://puu.sh/oCAvt/4c83f1b1f7.png

But the better way is to find that Widget Reference, wherever you created it and using that. So let’s say you created it inside your PlayerCharacter…like in here that I just did:

http://puu.sh/oCAHk/fc335c2592.png

Next, you go to your CoinBP:

http://puu.sh/oCAVX/63395cbbb0.png

Change Pawn to Character or wherever it is located at.