Fatal error: Uncaught Error: Class 'Symfony\Component\Serializer\Normalizer\AbstractObjectNormalizer' not found in /home1/heyerarc/public_html/updates/concrete5-8.5.5_remote_updater/concrete/vendor/symfony/serializer/Normalizer/ObjectNormalizer.php:27 Stack trace: #0 {main} thrown in /home1/heyerarc/public_html/updates/concrete5-8.5.5_remote_updater/concrete/vendor/symfony/serializer/Normalizer/ObjectNormalizer.php on line 27