### 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
if (last_date == date) {
				continue;
			}
			Ref<Script> scr = edited_res;
			if (scr != nullptr) {
				Ref<Script> rel_scr = ResourceLoader::load(scr->get_path(), scr->get_class(), ResourceFormatLoader::CACHE_MODE_IGNORE);
				ERR_CONTINUE(!rel_scr.is_valid());
				scr->set_source_code(rel_scr->get_source_code());
				scr->set_last_modified_time(rel_scr->get_last_modified_time());
				scr->reload(true);
			}
			Ref<TextFile> text_file = edited_res;
			if (text_file != nullptr) {
				Error err;
				Ref<TextFile> rel_text_file = _load_text_file(text_file->get_path(), &err);
				ERR_CONTINUE(!rel_text_file.is_valid());
				text_file->set_text(rel_text_file->get_text());
				text_file->set_last_modified_time(rel_text_file->get_last_modified_time());
			}
		}
		se->reload_text();
	}
	disk_changed->hide();
	_update_script_names();
}
void ScriptEditor::open_script_create_dialog(const String &p_base_name, const String &p_base_path) {
	_menu_option(FILE_NEW);
	script_create_dialog->config(p_base_name, p_base_path);
}
void ScriptEditor::open_text_file_create_dialog(const String &p_base_path, const String &p_base_name) {