Plesk 12.0.18 only a white page appears in Roundcube

[Darkcallen]

Hi,

After the update to Plesk 12.0.18 only a white page appears in Roundcube. Unfortunately also reinstall did not remedy.
What's the problem here?
OS Debian 7.1
Plesk version 12.0.18 Update # 5, last updated at June 30, 2014 09:02 PM
Roundcube 1.0.0
http://webmail.2-enjoy.de/roundcube/index.php

LG Darkcallen

 

[IgorG]

On this page I see only Roundcube login screen. What is the problem exactly?