Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\DependencyInjection\Extension" not found in /var/www/html/vendor/symfony/framework-bundle/DependencyInjection/FrameworkExtension.php:173 Stack trace: #0 {main} thrown in /var/www/html/vendor/symfony/framework-bundle/DependencyInjection/FrameworkExtension.php on line 173