Fatal error: Uncaught Error: Class "APP\handler\Handler" not found in C:\xampp\htdocs\ojs\lib\pkp\controllers\modals\submission\ViewSubmissionMetadataHandler.php:26 Stack trace: #0 {main} thrown in C:\xampp\htdocs\ojs\lib\pkp\controllers\modals\submission\ViewSubmissionMetadataHandler.php on line 26