Cast to VRPlayer Failed

hey everyone,
i tried to to cast from my player controller bp to my VRPawn BP.
So in the eventgraph from my player controller bp it should look like:

Begin Play -> Cast to VRPlayer (Object is [GetPlayerPawn]) -> Promote to Variable

But everytime i start nothing happened. Just cast failed…

Gamemode: MyGameMode

Default Pawn: VRPawn
HUD Class: HUD
PlayerController: MutliPc
GameState: GameStateBase
PlayerState: PlayerStae
Spec Class: SpectatorPawn

I hope you can help me…