I have - ISPConfig 3.1.1p1 - Debian Wheezy - Roundcube 0.7.2-9+deb7u5 - dovecot for POP3 and IMAP I can log in to Webmail, send and receive e-mails. But when trying to go to Settings in the Roundcube UI, it shows HTTP error 500 and text that says page does not work. I have installed the ispconfig roundcube plugins, following https://www.howtoforge.com/using-ro...-debian-wheezy-apache2#-configuring-roundcube My knowledge about roundcube is very limeted, and I have no idea what is wrong. Logs do not seem to show anything useful, at least I do not identify any useful entries. ISPConfig test script does not report errors. Another thing that may be related is a user said his address book in RoundCube has gone missing. I upgraded the underlying operating system and ISPConfig, I believe this has caused these troubles.