Add child null instance bug

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1

4.1.2

Question

so i tried to add a scene into another scene for the game im making but everytime i try to run the game the error is: “attempt to call funcion add child in base null instance on a null instance”. Can anyone help? Here is the code:

func xp_bar():

var xpbar = $"../CanvasLayer/xpbar"

xpbar.value = global.player_xp_gain

if xpbar.value >= xpbar.max_value:

	global.counter += 1

	global.player_xp_gain = 0

	print("level ", global.counter)

	xpbar.max_value = 100 * global.counter

	var options = 0

            var options_max = 3

	while options < options_max:

     var option_choice=item_option.instantiate()
		upgrade_options.add_child(option_choice)

		options += 1

also forgot to say that the function is put into ready func…

2

I’m not very good at coding, but I think the problem might be what you’re adding the child to and what youre adding.

heres what i did for an example

var food1 = preload(res://node_2d.tscn)
var food2 = food1.instantiate()
var food3 = $Camera2D
add_child(food2)
food3.add_child(food2)

you dont really say what “upgrade_options” is nor do you say what “option_choice” is.
the debug is basically telling you that both of those things are null.
so make sure the item_option is something like
||var food1 = preload(res://node_2d.tscn)||
and then make sure upgrade_options is something like
var food3 = $Camera2D
it should be green
you could also just do add child(without the upgrade_options) and it will add the child to the node you have the script on
for example:
add_child(option_choice)
and then it will add the child without needing what to add it to.