### 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
file_menu->set_item_disabled(file_menu->get_item_index(FILE_OPEN_PREV), previous_scenes.is_empty());
	_update_undo_redo_allowed();
}
void EditorNode::_update_file_menu_closed() {
	file_menu->set_item_disabled(file_menu->get_item_index(FILE_OPEN_PREV), false);
}
VBoxContainer *EditorNode::get_main_screen_control() {
	return main_screen_vbox;
}
void EditorNode::editor_select(int p_which) {
	static bool selecting = false;
	if (selecting || changing_scene) {
		return;
	}
	ERR_FAIL_INDEX(p_which, editor_table.size());
	if (!main_editor_buttons[p_which]->is_visible()) { 
		return;
	}
	selecting = true;
	for (int i = 0; i < main_editor_buttons.size(); i++) {
		main_editor_buttons[i]->set_pressed(i == p_which);
	}
	selecting = false;
	EditorPlugin *new_editor = editor_table[p_which];
	ERR_FAIL_COND(!new_editor);
	if (editor_plugin_screen == new_editor) {
		return;