Fatal error: Uncaught Error: Class 'Symfony\Component\DependencyInjection\Loader\FileLoader' not found in /var/www/typo3/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php:36 Stack trace: #0 {main} thrown in /var/www/typo3/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php on line 36