Fatal error: Uncaught Error: Class "Symfony\Component\Console\Application" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Command/DbDumpApplication.php:11 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Command/DbDumpApplication.php on line 11