Fatal error: Uncaught Error: Interface 'Symfony\Contracts\Service\ServiceSubscriberInterface' not found in /home/devmecseminars/public_html/mec/vendor/symfony/dependency-injection/ServiceSubscriberInterface.php:21 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/symfony/dependency-injection/ServiceSubscriberInterface.php on line 21