Fatal error: Uncaught Error: Class "ApiPlatform\Serializer\AbstractCollectionNormalizer" not found in /var/www/crm_killing_ninja/vendor/api-platform/core/src/Hal/Serializer/CollectionNormalizer.php:29 Stack trace: #0 {main} thrown in /var/www/crm_killing_ninja/vendor/api-platform/core/src/Hal/Serializer/CollectionNormalizer.php on line 29