ISPconfig 3 problem - email page

Hi,

i have vps and install hosting from this HowToForge -> https://www.howtoforge.com/tutorial/perfect-server-debian-8-jessie-apache-bind-dovecot-ispconfig-3/

ISPconfig 3.1.1p1

I Have problem in email page - when i want configure email - i see blank page.



-------------
edit

I find My problem

In /etc/apache2/conf-enabled/roundcube.conf i must remove :
Alias /mail /var/lib/roundcube