RoundCube error: config.inc.php was not found.

This tutorial shows you how to solve the RoundCube webmail error message:

config.inc.php was not found.

on an ISPConfig Debian server that uses Nginx as the web server.

Solution

RoundCube webmail is accessed on an ISPConfig Nginx web server through the apps vhost. The PHP-FPM of the apps vhost is running under the user and group ispapps. To fix the above error you'll have to change the owner of some RoundCube files.

Run these commands as root user to apply the changes.

chown root:ispapps /etc/roundcube/debian-db.php
chmod 640 /etc/roundcube/debian-db.php
chown root:ispapps /etc/roundcube/config.inc.php
chmod 640 /etc/roundcube/config.inc.php
chown -R ispapps:adm /var/log/roundcube
chmod -R 750 /var/log/roundcube
chown -R ispapps:ispapps /var/lib/roundcube/temp
chmod -R 750 /var/lib/roundcube/temp