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