Fatal error: Uncaught Error: Interface "Drupal\Core\Config\StorageInterface" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Config/NullStorage.php:19 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Config/NullStorage.php on line 19