Fatal error: Uncaught Error: Interface "Symfony\Component\Mime\Encoder\EncoderInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/symfony/mime/Encoder/QpEncoder.php:19 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/symfony/mime/Encoder/QpEncoder.php on line 19