https://relaunch.pdir.de/docs/en/contao/extensions/advanced-classes/requirements/Note Advanced Classes is compatible with Contao 4.4 or higher. Contao 4 Contao 4 requires a web server such as Apache or NGINX with PHP and MySQL support. Advanced Classes requires Contao 4.4 or higher and PHP 5.6. Tip We recommend Contao 4.9 with PHP 7.1 or higher.Hugoen-US