Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in /home/amper418/shopv2.amperio.ch/vendor/shopware/core/Content/MailTemplate/Service/Event/MailSentEvent.php:18 Stack trace: #0 {main} thrown in /home/amper418/shopv2.amperio.ch/vendor/shopware/core/Content/MailTemplate/Service/Event/MailSentEvent.php on line 18