Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in /home/airbuahc/public_html/website-subscription-management-system/vendor/symfony/mailer/Event/SentMessageEvent.php:20 Stack trace: #0 {main} thrown in /home/airbuahc/public_html/website-subscription-management-system/vendor/symfony/mailer/Event/SentMessageEvent.php on line 20