Fatal error: Uncaught Error: Interface "OCP\Activity\IFilter" not found in /home/tzuovhm/tzuovhm/apps/dav/lib/CalDAV/Activity/Filter/Calendar.php:12 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/apps/dav/lib/CalDAV/Activity/Filter/Calendar.php on line 12