Fatal error: Uncaught Error: Class 'Symfony\Component\HttpKernel\Exception\HttpException' not found in /home/app/htdocs/message_gateway/vendor/symfony/http-kernel/Exception/UnprocessableEntityHttpException.php:17 Stack trace: #0 {main} thrown in /home/app/htdocs/message_gateway/vendor/symfony/http-kernel/Exception/UnprocessableEntityHttpException.php on line 17