Fatal error: Uncaught Error: Interface "Symfony\Component\Mailer\Transport\TransportInterface" not found in C:\xampp\htdocs\ojs\lib\pkp\classes\mail\transport\PHPMailerTransport.php:28 Stack trace: #0 {main} thrown in C:\xampp\htdocs\ojs\lib\pkp\classes\mail\transport\PHPMailerTransport.php on line 28