Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in D:\programs\xampp\htdocs\blog\vendor\symfony\mailer\Event\SentMessageEvent.php:20 Stack trace: #0 {main} thrown in D:\programs\xampp\htdocs\blog\vendor\symfony\mailer\Event\SentMessageEvent.php on line 20