Fatal error: Uncaught Error: Class "Symfony\Component\Mime\Part\AbstractPart" not found in /srv/www/sites/public/starter-projects/vendor/symfony/mime/Part/AbstractMultipartPart.php:19 Stack trace: #0 {main} thrown in /srv/www/sites/public/starter-projects/vendor/symfony/mime/Part/AbstractMultipartPart.php on line 19