Fatal error: Uncaught Error: Class "Symfony\Component\Serializer\Normalizer\AbstractNormalizer" not found in /home/rogertabor/public_html/updates/concrete-cms-9.1.1/concrete/vendor/symfony/serializer/Normalizer/AbstractObjectNormalizer.php:36 Stack trace: #0 {main} thrown in /home/rogertabor/public_html/updates/concrete-cms-9.1.1/concrete/vendor/symfony/serializer/Normalizer/AbstractObjectNormalizer.php on line 36