Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\Extension\Extension" not found in /srv/www/sites/public/starter-projects/vendor/symfony/http-kernel/DependencyInjection/Extension.php:21 Stack trace: #0 {main} thrown in /srv/www/sites/public/starter-projects/vendor/symfony/http-kernel/DependencyInjection/Extension.php on line 21