Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\Extension\AbstractExtension" not found in /var/www/crm_killing_ninja/core/backend/DependecyInjection/Metadata/MetadataExtension.php:39 Stack trace: #0 {main} thrown in /var/www/crm_killing_ninja/core/backend/DependecyInjection/Metadata/MetadataExtension.php on line 39