Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in C:\Servers\htdocs\inventory.fitzalan.co.uk\vendor\symfony\mailer\Event\SentMessageEvent.php:20 Stack trace: #0 {main} thrown in C:\Servers\htdocs\inventory.fitzalan.co.uk\vendor\symfony\mailer\Event\SentMessageEvent.php on line 20