### 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
EditorPropertyNameProcessor *epnp = memnew(EditorPropertyNameProcessor);
	add_child(epnp);
	PortableCompressedTexture2D::set_keep_all_compressed_buffers(true);
	Input::get_singleton()->set_use_accumulated_input(true);
	Resource::_get_local_scene_func = _resource_get_edited_scene;
	RenderingServer::get_singleton()->set_debug_generate_wireframes(true);
	AudioServer::get_singleton()->set_enable_tagging_used_audio_streams(true);
	
	if (NavigationServer3D::get_singleton()->get_debug_enabled()) {
		NavigationServer3D::get_singleton()->set_active(true);
	} else {
		NavigationServer3D::get_singleton()->set_active(false);
	}
	
	PhysicsServer3D::get_singleton()->set_active(false);
	PhysicsServer2D::get_singleton()->set_active(false);
	
	ScriptServer::set_scripting_enabled(false);
	EditorHelp::generate_doc(); 
	SceneState::set_disable_placeholders(true);
	ResourceLoader::clear_translation_remaps(); 
	ResourceLoader::clear_path_remaps();
	ResourceLoader::set_create_missing_resources_if_class_unavailable(true);
	Input *id = Input::get_singleton();
	if (id) {
		if (!DisplayServer::get_singleton()->is_touchscreen_available() && Input::get_singleton()) {
			
			id->set_emulate_touch_from_mouse(false);
		}