Fatal error: Uncaught Error: Interface "Drupal\Component\Plugin\Derivative\DeriverInterface" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Plugin/Discovery/ContainerDeriverInterface.php:12 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Plugin/Discovery/ContainerDeriverInterface.php on line 12