Redmine

My infos :

[01:13 PM]-[root@packer-virtualbox-iso]-[/opt/redmine-2.5]-[svn] B
B# RAILS_ENV=production ruby script/about

Environment:
  Redmine version                2.5.2.stable.13345
  Ruby version                   1.8.7-p352 (2011-06-30) [x86_64-linux]
  Rails version                  3.2.19
  Environment                    production
  Database adapter               Mysql2
SCM:
  Subversion                     1.8.0
  Git                            1.7.9.5
  Filesystem
Redmine plugins:
  no plugin installed

My VHOST :

 <VirtualHost *>
   SetEnv RAILS_ENV production
   ServerName redmine.dev
   DocumentRoot "/opt/redmine-2.5/public" 
   <Directory "/opt/redmine-2.5/public">
     Options Indexes FollowSymLinks MultiViews
     AllowOverride All
     Require all granted
   </Directory>

   ErrorLog "/var/log/apache2/redmine_error.log" 
   ServerSignature Off
   CustomLog "/var/log/apache2/redmine_access.log" combined

   ServerAlias redmine.dev

   #ProxyPassMatch ^/(.*\.php(/.*)?)$ fcgi://127.0.0.1:3000/opt/redmine-2.5/public/$1
   ProxyPass / http://127.0.0.1:3000/
   ProxyPassReverse / http://127.0.0.1:3000/

 </VirtualHost>

And when I go to "redmine.dev" I have this error :

Internal error

An error occurred on the page you were trying to access.
If you continue to experience problems please contact your Redmine administrator for assistance.

If you are the Redmine administrator, check your log files for details about the error.

Back

I really don't understand, this is a clean install with apache2 and mysql, with no error log. It's my first install of redmine and ruby on Ubuntu so I maybe miss something.

Thanks.