Fatal error: Uncaught Error: Interface "Drupal\Core\Password\PasswordInterface" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Password/PhpassHashedPassword.php:13 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Password/PhpassHashedPassword.php on line 13