Fatal error: Uncaught Error: Class "Symfony\Component\HttpFoundation\Exception\UnexpectedValueException" not found in /var/www/html/app/vendor/symfony/http-foundation/Exception/ConflictingHeadersException.php:19 Stack trace: #0 {main} thrown in /var/www/html/app/vendor/symfony/http-foundation/Exception/ConflictingHeadersException.php on line 19