Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in /home/bimmertest/BookStack/vendor/ssddanbrown/symfony-mailer/Event/MessageEvent.php:23 Stack trace: #0 {main} thrown in /home/bimmertest/BookStack/vendor/ssddanbrown/symfony-mailer/Event/MessageEvent.php on line 23