i followed this howto to install roundcube (i removed squirrelmail which was installed previously): https://www.howtoforge.com/using-roundcube-webmail-with-ispconfig-3-on-debian-wheezy-apache2 everything worked right off the bat, i could log in, saw the mailbox contents and even sent a mail. nice! unfortunately, when i click on "settings", i only get a blank page and the following line in the roundcube error log: PHP Fatal error: Class 'rcube' not found in /var/lib/roundcube/plugins/ispconfig3_account/ispconfig3_account.php on line 13 i've been trying to fix this for the past few hours, but no success so far.. what am i missing here? regards, al edit. i found a solution! turns out the roundcube from debian's standard sources is too old to play well with my php version (or something along these lines). i fixed it like suggested in this thread: https://www.howtoforge.com/communit...h-ispconfig-3-on-debian-wheezy-apache2.69920/ now it works & looks pretty!