### Godot version

4.2 eca6f0e

### System information

Windows 10 x64

### Issue description


https://github.com/godotengine/godot/assets/2223172/a2796263-4e2e-4b14-a080-b3ad034cc141



### Steps to reproduce

1. Add SubViewport
2. Add Sprite2D
3. Set spirte's texture to ViewportTexture
4. Create new scene
5. Instance the new scene inside the scene with viewport
6. Make sure both scenes are opened
7. Go to instance scene and save it
8. Go to viewport scene

You will see error spam. Reloading the scene fixes it.

### Minimal reproduction project

[vip.zip](https://github.com/godotengine/godot/files/12292386/vip.zip)

bool use_hdr_2d = false;
	bool gen_mipmaps = false;
	bool snap_controls_to_pixels = true;
	bool snap_2d_transforms_to_pixel = false;
	bool snap_2d_vertices_to_pixel = false;
	bool physics_object_picking = false;
	bool physics_object_picking_sort = false;
	List<Ref<InputEvent>> physics_picking_events;
	ObjectID physics_object_capture;
	ObjectID physics_object_over;
	Transform3D physics_last_object_transform;
	Transform3D physics_last_camera_transform;
	ObjectID physics_last_id;
	bool handle_input_locally = true;
	bool local_input_handled = false;
	
	HashMap<ObjectID, uint64_t> physics_2d_mouseover;
	
	HashMap<Pair<ObjectID, int>, uint64_t, PairHash<ObjectID, int>> physics_2d_shape_mouseover;
	
	void _cleanup_mouseover_colliders(bool p_clean_all_frames, bool p_paused_only, uint64_t p_frame_reference = 0);
	Ref<World2D> world_2d;
	StringName input_group;
	StringName gui_input_group;
	StringName shortcut_input_group;
	StringName unhandled_input_group;
	StringName unhandled_key_input_group;
	void _update_audio_listener_2d();
	bool disable_3d = false;
	void _propagate_viewport_notification(Node *p_node, int p_what);