error with instancing a ball in my pong game in godot

Question

Hello I am working on a pong game in godot. Everything is going well so far but I recieve this error in my debugger:

E 0:01:55.112 body_set_shape_as_one_way_collision: Can't change this state while flushing queries. Use call_deferred() or set_deferred() to change monitoring state instead.

<C++ Error> Condition "body->get_space() && flushing_queries" is true.

<C++ Source> servers/physics_2d/physics_2d_server_sw.cpp:739 @ body_set_shape_as_one_way_collision()

AddBall.gd:18 @ _on_Area2D_body_entered()

Here is my code for instancing a duplicate ball:

extends Node2D

var collect = false
var ballscene = null

func _ready():
    $Area2D/AnimatedSprite.play("Spin")

func _on_Area2D_body_entered(body):
    #print(body.name)
    if body.name=="Ball"&&collect==false:
        collect = true
        $Collection.play()
        $AnimationPlayer.play("Fade")
        $Area2D/AnimatedSprite.stop()
        var ball =  load("res://Scenes/BallDuplicate.tscn")
        ballscene = ball.instance()
        find_parent("SpawnManager").get_node("BallDuplicate").add_child(ballscene)
        queue_free()
        

Yes, I instance the ball in the power up and not my spawn manager.

Answer 1

As the error message recommends, you should postpone your node tree changes with call_deffered() as you are not allowed to kick in with adding another rigid bodies to the scene during collision processing.

extends Node2D

var collect = false
var ballscene = null

func CollectFunc():
    if not collect:
        collect = true
        $Collection.play()
        $AnimationPlayer.play("Fade")
        $Area2D/AnimatedSprite.stop()
        var ball =  load("res://Scenes/BallDuplicate.tscn")
        ballscene = ball.instance()
        find_parent("SpawnManager").get_node("BallDuplicate").add_child(ballscene)
        queue_free()

func _ready():
    $Area2D/AnimatedSprite.play("Spin")

func _on_Area2D_body_entered(body):
    #print(body.name)
    if body.name=="Ball":
        call_deffered("CollectFunc")