Fatal error: Uncaught Error: Class "Drupal\hal\Normalizer\EntityReferenceItemNormalizer" not found in /home/www/drupal8/test/modules/webform/src/Normalizer/WebformEntityReferenceItemNormalizer.php:11 Stack trace: #0 {main} thrown in /home/www/drupal8/test/modules/webform/src/Normalizer/WebformEntityReferenceItemNormalizer.php on line 11