Fatal error: Uncaught Error: Class 'Symfony\Component\Mime\Encoder\QpEncoder' not found in C:\xampp\htdocs\plugins\Symfony\Component\Mime\Encoder\QpMimeHeaderEncoder.php:17 Stack trace: #0 {main} thrown in C:\xampp\htdocs\plugins\Symfony\Component\Mime\Encoder\QpMimeHeaderEncoder.php on line 17