Fatal error: Uncaught Error: Class 'Symfony\Component\Mime\Part\AbstractPart' not found in /mnt/volume_lon1_01/backend/admin/vendor/symfony/mime/Part/TextPart.php:24 Stack trace: #0 {main} thrown in /mnt/volume_lon1_01/backend/admin/vendor/symfony/mime/Part/TextPart.php on line 24