### 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
Array rc = EditorSettings::get_singleton()->get_project_metadata("recent_files", "scenes", Array());
	recent_scenes->clear();
	String path;
	for (int i = 0; i < rc.size(); i++) {
		path = rc[i];
		recent_scenes->add_item(path.replace("res:", ""), i);
	}
	recent_scenes->add_separator();
	recent_scenes->add_shortcut(ED_SHORTCUT("editor/clear_recent", TTR("Clear Recent Scenes")));
	recent_scenes->reset_size();
}
void EditorNode::_quick_opened() {
	Vector<String> files = quick_open->get_selected_files();
	bool open_scene_dialog = quick_open->get_base_type() == "PackedScene";
	for (int i = 0; i < files.size(); i++) {
		String res_path = files[i];
		List<String> scene_extensions;
		ResourceLoader::get_recognized_extensions_for_type("PackedScene", &scene_extensions);
		if (open_scene_dialog || scene_extensions.find(files[i].get_extension().to_lower())) {
			open_request(res_path);
		} else {
			load_resource(res_path);
		}
	}
}
void EditorNode::_project_run_started() {