I maybe wrong on this but but here’s my take on it (warning pseudo code)…
In the blueprint you have UnPosses(target = self). “self” in this case is the PlayerController, you don’t want to UnPossess(a playercontroller) you want to UnPossess(a pawn). Not sure if this will fix your issue, you need to change your target to the Pawn currently possessed by the player controller…
It looks like you could just drag the blue wire from GetPlayerPawn() to UnPossess, not Possess. You need to possess some other Pawn when you press K, not PlayerPawn, as the “PlayerPawn” is the one that is already currently possessed.
Also, is the Player Index 1? I was under the impression the first player was player 0.