### Godot version

4.1 rc3

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

This™
![image](https://github.com/godotengine/godot/assets/2223172/cb33110f-a5b0-400a-951f-3fa425f05714)

It can still happen, but it's more difficult to trigger.

### Steps to reproduce

1. Create a new scene with a Control node
2. Add Theme to the Control
3. Open Theme Editor
4. Clear the `theme` property in Control
5. Save, with Theme Editor opened
6. Restart

### Minimal reproduction project

N/A
return changing_scene;
}
void EditorNode::set_current_scene(int p_idx) {
	
	if (editor_data.get_scene_path(p_idx) != "" && editor_data.get_edited_scene_root(p_idx)) {
		editor_folding.save_scene_folding(editor_data.get_edited_scene_root(p_idx), editor_data.get_scene_path(p_idx));
	}
	if (editor_data.check_and_update_scene(p_idx)) {
		if (editor_data.get_scene_path(p_idx) != "") {
			editor_folding.load_scene_folding(editor_data.get_edited_scene_root(p_idx), editor_data.get_scene_path(p_idx));
		}
		EditorUndoRedoManager::get_singleton()->clear_history(false, editor_data.get_scene_history_id(p_idx));
	}
	changing_scene = true;
	editor_data.save_edited_scene_state(editor_selection, &editor_history, _get_main_scene_state());
	if (get_editor_data().get_edited_scene_root()) {
		if (get_editor_data().get_edited_scene_root()->get_parent() == scene_root) {
			scene_root->remove_child(get_editor_data().get_edited_scene_root());
		}