### 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
}
	if (p_clear_errors) {
		load_errors->clear();
	}
	String lpath = ProjectSettings::get_singleton()->localize_path(p_scene);
	if (!lpath.begins_with("res:")) {
		show_accept(TTR("Error loading scene, it must be inside the project path. Use 'Import' to open the scene, then save it inside the project path."), TTR("OK"));
		opening_prev = false;
		return ERR_FILE_NOT_FOUND;
	}
	int prev = editor_data.get_edited_scene();
	int idx = editor_data.add_edited_scene(-1);
	if (!editor_data.get_edited_scene_root() && editor_data.get_edited_scene_count() == 2) {
		_remove_edited_scene();
	} else if (!p_silent_change_tab) {
		_scene_tab_changed(idx);
	} else {
		set_current_scene(idx);
	}
	dependency_errors.clear();
	Error err;
	Ref<PackedScene> sdata = ResourceLoader::load(lpath, "", ResourceFormatLoader::CACHE_MODE_REPLACE, &err);
	if (!sdata.is_valid()) {
		_dialog_display_load_error(lpath, err);
		opening_prev = false;
		if (prev != -1) {
			set_current_scene(prev);
			editor_data.remove_scene(idx);
		}
		return ERR_FILE_NOT_FOUND;