Fatal error: Uncaught Error: Class 'Symfony\Component\DependencyInjection\Dumper\Dumper' not found in /var/www/typo3/vendor/symfony/dependency-injection/Dumper/GraphvizDumper.php:31 Stack trace: #0 {main} thrown in /var/www/typo3/vendor/symfony/dependency-injection/Dumper/GraphvizDumper.php on line 31