Fatal error: Uncaught Error: Class 'Symfony\Contracts\EventDispatcher\Event' not found in /home/mattiapa/cloud2.mprnl.fr/owncloud/apps/workflow/lib/Engine/Event/ValidateFlow.php:22 Stack trace: #0 {main} thrown in /home/mattiapa/cloud2.mprnl.fr/owncloud/apps/workflow/lib/Engine/Event/ValidateFlow.php on line 22