Repeated log entry

Messenger is working just fine but I have a lot of this in the logs:

Error: Call to undefined method IPS\core\Messenger\Conversation::unread() (0)
#0 /home/sosinvisioncom/public_html/system/Notification/Inline.php(251): IPS\core\extensions\core\Notifications\MyStuff->parse_mention()
#1 /home/sosinvisioncom/public_html/system/Notification/Table.php(121): IPS\Notification\Inline->getData()
#2 /home/sosinvisioncom/public_html/applications/core/modules/front/system/notifications.php(83): IPS\Notification\Table->getRows()
#3 /home/sosinvisioncom/public_html/system/Dispatcher/Controller.php(139): IPS\core\modules\front\system\notifications->manage()
#4 /home/sosinvisioncom/public_html/system/Dispatcher/Dispatcher.php(169): IPS\Dispatcher\Controller->execute()
#5 /home/sosinvisioncom/public_html/index.php(16): IPS\Dispatcher->run()
#6 {main}