Redmine

I'm just installing redmine for a friend of mine.
He has debian 7 installed.
The Installer went through everything without a problem.
But as soon as I look at redmine from the web I only get this:

I'm not shure what I set wrong.

Here's the apache2 config file:

<VirtualHost xxx.xxx.xxx.xxx:443>
    ServerAdmin webmaster@xxxxxxxx
    ServerName project.xxxxxxxx.tld
    DocumentRoot /var/www/project/public
    SSLEngine on

    #   A self-signed (snakeoil) certificate can be created by installing
    #   the ssl-cert package. See
    #   /usr/share/doc/apache2.2-common/README.Debian.gz for more info.
    #   If both key and certificate are stored in the same file, only the
    #   SSLCertificateFile directive is needed.
    SSLCertificateFile    /etc/ssl/xxxxxxxx/host.pem
    SSLCertificateKeyFile /etc/ssl/xxxxxxxx/host.key
    SSLCertificateChainFile /etc/ssl/xxxxxxxx/host.cert
    BrowserMatch "MSIE [2-6]" \
        nokeepalive ssl-unclean-shutdown \
        downgrade-1.0 force-response-1.0
    # MSIE 7 and newer should be able to use keepalive
    BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown

    <Directory />
        Options FollowSymLinks
        AllowOverride None
    </Directory>
        RailsEnv production
        SetEnv X_DEBIAN_SITEID "default" 
        SetEnv RAILS_RELATIVE_URL_ROOT "/" 
    <Directory /var/www/project/public/>
        Options -MultiViews
        Order allow,deny
        Allow from all
        AllowOverride none
        Satisfy Any
                Options FollowSymLinks
                RailsBaseURI /
                PassengerResolveSymlinksinDocumentRoot off
                AllowOverride None
        </Directory>

    ErrorLog ${APACHE_LOG_DIR}/project/error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    CustomLog ${APACHE_LOG_DIR}/project/access.log combined

</VirtualHost>

If I access one of the files using the base url and the link it works, the files are accessable.
It seems that a base ref is missing, but I don't know why.
I have the same stuff with almost the same config running everywhere
Please help me.

Chris