Fatal error: Uncaught Error: Class "Drupal\Component\Plugin\Factory\DefaultFactory" not found in /home/www/drupal8/test/core/lib/Drupal/Component/Plugin/Factory/ReflectionFactory.php:11 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Component/Plugin/Factory/ReflectionFactory.php on line 11