Fatal error: Uncaught Error: Class "Symfony\Component\Mime\Header\AbstractHeader" not found in /home1/aihika/public_html/elephant-society/vendor_old/symfony/mime/Header/MailboxListHeader.php:22 Stack trace: #0 {main} thrown in /home1/aihika/public_html/elephant-society/vendor_old/symfony/mime/Header/MailboxListHeader.php on line 22