PHP Fatal error: Uncaught Error: Call to a member function getId()

Hi,
I noticed the following php error appearing in the error log once every two or three days.
OJS: 3.2.1.1

OS platform Linux
PHP version 7.2.33
Apache version Apache
Database driver mysqli
Database server version 10.3.24-MariaDB
PHP Fatal error:  Uncaught Error: Call to a member function getId() on null in /home/seisense/journal.seisense.com/lib/pkp/controllers/grid/notifications/TaskNotificationsGridHandler.inc.php:30

Stack trace:
#0 /home/seisense/journal.seisense.com/lib/pkp/classes/controllers/grid/GridHandler.inc.php(314): TaskNotificationsGridHandler->loadData(Object(Request), NULL)
#1 /home/seisense/journal.seisense.com/lib/pkp/classes/controllers/grid/GridHandler.inc.php(1032): GridHandler->getGridDataElements(Object(Request))
#2 /home/seisense/journal.seisense.com/lib/pkp/classes/controllers/grid/GridHandler.inc.php(923): GridHandler->renderGridBodyPartsInternally(Object(Request))
#3 /home/seisense/journal.seisense.com/lib/pkp/classes/controllers/grid/GridHandler.inc.php(645): GridHandler->doSpecificFetchGridActions(Array, Object(Request), Object(TemplateManager))
#4 /home/seisense/journal.seisense.com/lib/pkp/classes/core/PKPRouter.inc.php(391): GridHandler->fetchGrid(Array, Object(Request))
#5 /home/seisense/journal.seisense.com/lib/pkp/cla in /home/seisense/journal.seisense.com/lib/pkp/controllers/grid/notifications/TaskNotificationsGridHandler.inc.php on line 30

Thanks and look forward to hearing an expert solution.