### 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 (atidx == -1) {
				
				for (WindowWrapper *wrapper : floating_docks) {
					if (wrapper->get_meta("dock_name") == name) {
						if (restore_window_on_load && floating_docks_dump.has(name)) {
							_restore_floating_dock(floating_docks_dump[name], wrapper, i);
							return;
						} else {
							_dock_floating_close_request(wrapper);
							atidx = wrapper->get_meta("dock_index");
						}
					}
				}
				
				continue;
			}
			if (atidx == i) {
				dock_slot[i]->move_child(node, 0);
			} else if (atidx != -1) {
				dock_slot[atidx]->remove_child(node);
				if (dock_slot[atidx]->get_tab_count() == 0) {
					dock_slot[atidx]->hide();
				}
				dock_slot[i]->add_child(node);
				dock_slot[i]->move_child(node, 0);
				dock_slot[i]->set_tab_title(0, TTRGET(node->get_name()));
				dock_slot[i]->show();
			}
			WindowWrapper *wrapper = Object::cast_to<WindowWrapper>(node);