Fatal error: Uncaught Error: Class 'Whoops\Handler\Handler' not found in /mnt/volume_lon1_01/backend/admin/vendor/filp/whoops/src/Whoops/Handler/XmlResponseHandler.php:17 Stack trace: #0 {main} thrown in /mnt/volume_lon1_01/backend/admin/vendor/filp/whoops/src/Whoops/Handler/XmlResponseHandler.php on line 17