Fatal error: Uncaught Error: Class "PKP\core\PKPBaseController" not found in /var/www/html/lib/pkp/api/v1/announcements/PKPAnnouncementController.php:47 Stack trace: #0 {main} thrown in /var/www/html/lib/pkp/api/v1/announcements/PKPAnnouncementController.php on line 47