В логах выскочила вот такая ошибка:

PHP Fatal error:  Uncaught InvalidArgumentException: Please make sure the folder '/usr/local/ispconfig/interface/lib/classes/IDS/../../../temp' is writable in /usr/local/ispconfig/interface/lib/classes/IDS/Monitor.php

Решение простое:

chmod 660 /usr/local/ispconfig/interface/lib/classes/IDS/../../../temp