### 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
}
			_proceed_closing_scene_tabs();
		} break;
		case FILE_QUIT: {
			project_run_bar->stop_playing();
			_exit_editor(EXIT_SUCCESS);
		} break;
		case RUN_PROJECT_MANAGER: {
			project_run_bar->stop_playing();
			_exit_editor(EXIT_SUCCESS);
			String exec = OS::get_singleton()->get_executable_path();
			List<String> args;
			for (const String &a : Main::get_forwardable_cli_arguments(Main::CLI_SCOPE_TOOL)) {
				args.push_back(a);
			}
			String exec_base_dir = exec.get_base_dir();
			if (!exec_base_dir.is_empty()) {
				args.push_back("--path");
				args.push_back(exec_base_dir);
			}
			args.push_back("--project-manager");
			Error err = OS::get_singleton()->create_instance(args);
			ERR_FAIL_COND(err);
		} break;
		case RELOAD_CURRENT_PROJECT: {
			restart_editor();
		} break;
	}
}
void EditorNode::_update_file_menu_opened() {