Fatal error: Uncaught Error: Class 'Symfony\Component\DependencyInjection\Extension\Extension' not found in /mnt/volume_lon1_01/backend/adminseppi/vendor/symfony/http-kernel/DependencyInjection/Extension.php:21 Stack trace: #0 {main} thrown in /mnt/volume_lon1_01/backend/adminseppi/vendor/symfony/http-kernel/DependencyInjection/Extension.php on line 21