Fatal error: Uncaught TypeError: PKP\pages\announcement\AnnouncementHandler::isAnnouncementsEnabled(): Return value must be of type bool, null returned in /var/www/html/ojs/lib/pkp/pages/announcement/AnnouncementHandler.php:107 Stack trace: #0 /var/www/html/ojs/lib/pkp/pages/announcement/AnnouncementHandler.php(76): PKP\pages\announcement\AnnouncementHandler->isAnnouncementsEnabled() #1 [internal function]: PKP\pages\announcement\AnnouncementHandler->view() #2 /var/www/html/ojs/lib/pkp/classes/core/PKPRouter.php(334): call_user_func() #3 /var/www/html/ojs/lib/pkp/classes/core/PKPPageRouter.php(278): PKP\core\PKPRouter->_authorizeInitializeAndCallRequest() #4 /var/www/html/ojs/lib/pkp/classes/core/Dispatcher.php(165): PKP\core\PKPPageRouter->route() #5 /var/www/html/ojs/lib/pkp/classes/core/PKPApplication.php(395): PKP\core\Dispatcher->dispatch() #6 /var/www/html/ojs/index.php(22): PKP\core\PKPApplication->execute() #7 {main} thrown in /var/www/html/ojs/lib/pkp/pages/announcement/AnnouncementHandler.php on line 107