Fatal error: Uncaught Error: Class "OCP\EventDispatcher\Event" not found in /home/tzuovhm/tzuovhm/nextcloud/apps/viewer/lib/Event/LoadViewer.php:35 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/nextcloud/apps/viewer/lib/Event/LoadViewer.php on line 35