Cron Jobs for your UNA haven't been executed from 2018/09/05 (according to this info). So you need to correct / setup it again in the Control Panel of your server. Cron command should have a view like
* * * * * __path to php__ -q __server_path_to_UNA__periodic/cron.php
You need to setup cron on your server no in UNA files, some hosting control panels offer interface for it (like cPanel), if you don't know how to set it up, please contact your hosting support