Fatal error: Uncaught Error: Class 'Symfony\Component\EventDispatcher\Event' not found in /home/lafaamicps/www/symfony/vendor/sonata-project/block-bundle/Event/BlockEvent.php:17 Stack trace: #0 {main} thrown in /home/lafaamicps/www/symfony/vendor/sonata-project/block-bundle/Event/BlockEvent.php on line 17