Using pawn sensing with blackboard

alright so i’m basically trying to use the pawn sensing component to check if the player has been seen with my AI.

So I have a key in my blackboard set to object player.
When my PawnHasbeenSeen from the pawnsensing component fires off I try and set the key in my blackboard to the pawn that was seen. So that my Behaviour tree will send my AI to walk towards the player.

The Problem- everytime I get in front of my AI to be seen the Engine crashes…