Fatal error: Uncaught Error: Class 'Symfony\Component\EventDispatcher\Event' not found in /home/eberhardschwarze/public_html/vendor/nelmio/security-bundle/ContentSecurityPolicy/Violation/Event.php:16 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/nelmio/security-bundle/ContentSecurityPolicy/Violation/Event.php on line 16