Hi, The file /var/cache/nagios/plugins-auto.cfg generated by update-nagios has the following permissions : -rw------- 1 nagios nagios 18496 Jan 5 17:17 plugins-auto.cfg So it can't be read by the CGI and the Nagios WEB interface can't works correctly until I set it to : -rw-r----- 1 nagios www-data 18496 Jan 5 17:17 plugins-auto.cfg Regards, Jerome.