My code worked perfectly and something happened, now, I don't know why, the player node returns null and all stop working.
extends KinematicBody2D
var motion = Vector2()
func _ready():
pass
func _physics_process(delta):
var player = get_parent().get_node("player")
position += (player.position - position)/50
look_at(player.position)
motion = move_and_collide(motion)