Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\Loader\YamlFileLoader" not found in /var/www/html/core/backend/DependecyInjection/Metadata/ParameterMergingYamlFileLoader.php:32 Stack trace: #0 {main} thrown in /var/www/html/core/backend/DependecyInjection/Metadata/ParameterMergingYamlFileLoader.php on line 32