Fatal error: Uncaught Error: Class "Symfony\Component\EventDispatcher\Event" not found in /home/steevedfem/ekolaweb/vendor/friendsofsymfony/user-bundle/Event/GroupEvent.php:18 Stack trace: #0 {main} thrown in /home/steevedfem/ekolaweb/vendor/friendsofsymfony/user-bundle/Event/GroupEvent.php on line 18