Error HTTP 500 access to RoundCube webmail after upgrade ISPConfig to 3.0.5.1

Get error "http 500 internal server error" when trying to access Roundcube webmail after upgrade ISPConfig to 3.0.5.1 (error still remains after upgrade again to 3.0.5.2)
- First check Roundcube error log at /var/log/roundcube
Found errors:
PHP Error: Failed to load plugin file /var/lib/roundcube/plugins/fail2ban/fail2ban.php in /usr/share/roundcube/program/include/rcube_plugin_api.php on line 196 (GET /webmail/)
- Check roundcube config in /var/lib/roundcube/config/main.inc.php for syntax
$rcmail_config['plugins'] = array('fail2ban');
Syntax is correct.
- Check /usr/share/roundcube/plugins/fail2ban/fail2ban.php. Found fail2ban ver 1.0 in directory plugins
- Try to upgrade fail2ban to ver 1.1 following directions below:
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Install the roundcube logger plugin form http://mattrude.com/projects/roundcube-fail2ban-plugin/.
Basically you have to download the above file (fail2ban.php) and paste it in the fail2ban folder in the plugins folder of roundcube: /usr/share/roundcube/plugins/fail2ban/fail2ban.php
This plugin will first create and then update the log file with each login attempt: /var/log/roundcube/userlogins

cd /usr/share/roundcube/plugins/fail2ban/
wget https://github.com/mattrude/rc-plugin-fail2ban
mv rc-plugin-fail2ban fail2ban.tgz
tar xvfz fail2ban.tgz

Extend the jail.local file that Falko suggests in The Perfect Server - Debian Squeeze (Debian 6.0) With BIND & Courier [ISPConfig 3]: /etc/fail2ban/jail.local

Last (and very important) don't forget to create the roundcube.conf file /etc/fail2ban/filter.d/roundcube.conf with the contents below:
----
[Definition]
failregex = FAILED login for .*. from
ignoreregex =
----
Sources: http://www.howtoforge.com/easy-roundcube-over-ssl-and-webmin-with-fail2ban-for-ispconfig-3-on-debian-squeeze
http://mattrude.com/projects/roundcube-fail2ban-plugin/
Restart fail2ban and apache but problem is not solved. Try to look at apache error log (not roundcube error log)
Found error
--------- 
SoftException in Application.cpp:221: File "/usr/share/roundcube/index.php" is not in document root of Vhost "/var/www/ispconfig/"
Premature end of script headers: index.php
---------
Anh here is solution for it
http://www.howtoforge.com/forums/showthread.php?t=60746
http://www.howtoforge.com/perfect-server-ubuntu-12.10-apache2-bind-dovecot-ispconfig-3-p4

Thank you HowToForge