Fatal error: Uncaught Error: Class "Drupal\jsonapi\Normalizer\NormalizerBase" not found in /home/qcsvlel/www/core/modules/jsonapi/src/Normalizer/RelationshipNormalizer.php:17 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/jsonapi/src/Normalizer/RelationshipNormalizer.php on line 17