Triggering blueprint event from BTTask

Hey
I’m trying to trigger the code that makes my enemy chase my player in a task from my Behavior Tree but it doesn’t work and I have no idea why, my cast works but it looks like there is a problem when in the Behaviour tree when my enemy spots the player, when my cast was failing the tree was stuck in the task but now that I have fixed the cast the tree freaks out whenever the ennemy spots the player…
Can anyone help?