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