Fatal error: Uncaught Error: Interface "Symfony\Component\Serializer\SerializerInterface" not found in /home/tubu/public_html/Drupal_CMS/cms/vendor/symfony/serializer/Serializer.php:46 Stack trace: #0 {main} thrown in /home/tubu/public_html/Drupal_CMS/cms/vendor/symfony/serializer/Serializer.php on line 46