Fatal error: Uncaught Error: Class "Symfony\Component\Mime\Part\AbstractMultipartPart" not found in /usr/www/unityweb/public/hms/vendor/symfony/mime/Part/Multipart/RelatedPart.php:20 Stack trace: #0 {main} thrown in /usr/www/unityweb/public/hms/vendor/symfony/mime/Part/Multipart/RelatedPart.php on line 20