### Godot version

3.5.1mono

### System information

windows10

### Issue description

Error message
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).
See "Steps to reproduce for details"

### Steps to reproduce

Set an external text editor
Create a script
Drop the script to the built-in text editor like this image:
![image](https://user-images.githubusercontent.com/119792950/209504041-039f2620-5e42-4c0f-8c41-cd24486fb3d2.png)
And got error message:
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).

### Minimal reproduction project

An empty project
se->convert_indent_to_tabs();
			}
		}
		Ref<TextFile> text_file = scr;
		if (text_file != nullptr) {
			se->apply_code();
			_save_text_file(text_file, text_file->get_path());
			break;
		} else {
			EditorNode::get_singleton()->save_resource(scr);
		}
		se->tag_saved_version();
	}
	disk_changed->hide();
}
void ScriptEditor::_res_saved_callback(const Ref<Resource> &p_res) {
	for (int i = 0; i < tab_container->get_tab_count(); i++) {
		ScriptEditorBase *se = Object::cast_to<ScriptEditorBase>(tab_container->get_tab_control(i));
		if (!se) {
			continue;
		}
		Ref<Resource> scr = se->get_edited_resource();
		if (scr == p_res) {
			se->tag_saved_version();
		}
	}
	_update_script_names();
	_trigger_live_script_reload();
}
void ScriptEditor::_scene_saved_callback(const String &p_path) {