Fatal error: Uncaught Error: Interface 'Symfony\Component\EventDispatcher\EventSubscriberInterface' not found in /home/eberhardschwarze/public_html/vendor/friendsofsymfony/http-cache-bundle/src/EventListener/FlashMessageListener.php:28 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/friendsofsymfony/http-cache-bundle/src/EventListener/FlashMessageListener.php on line 28