### 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
DisplayServer::get_singleton()->cursor_set_custom_image(Ref<Resource>());
	}
	singleton = this;
	EditorUndoRedoManager::get_singleton()->connect("version_changed", callable_mp(this, &EditorNode::_update_undo_redo_allowed));
	EditorUndoRedoManager::get_singleton()->connect("history_changed", callable_mp(this, &EditorNode::_update_undo_redo_allowed));
	TranslationServer::get_singleton()->set_enabled(false);
	
	if (!EditorSettings::get_singleton()) {
		EditorSettings::create();
	}
	FileAccess::set_backup_save(EDITOR_GET("filesystem/on_save/safe_save_on_backup_then_rename"));
	{
		int display_scale = EDITOR_GET("interface/editor/display_scale");
		switch (display_scale) {
			case 0:
				
				EditorScale::set_scale(EditorSettings::get_singleton()->get_auto_display_scale());
				break;
			case 1:
				EditorScale::set_scale(0.75);
				break;
			case 2:
				EditorScale::set_scale(1.0);
				break;
			case 3:
				EditorScale::set_scale(1.25);
				break;
			case 4:
				EditorScale::set_scale(1.5);
				break;