Document management not working

Hi,
I am now the administrator for our zimbra groupware (I was not the one that installed, that guy left).
Problem: If a user selects the document tab he gets:
Object not found!

The requested URL was not found on this server. The link on the referring page seems to be wrong or outdated. Please inform the author of that page about the error.

If you think this is a server error, please contact the webmaster.
Error 404

I've read the installation guide, according to the guide the documents feature is installed in the basic version. I also read the admin guide. There is a Global Documents account wiki@ourdomain.ch.
I also created a domain documents account docs@ourdomain.ch

in /opt/zimbra/wiki/Template
there are the following tempates:
Logo.gif _TemplateStyles_unused.wiki
_Footer.wiki _TitleBar.wiki
_Header.wiki _TocBodyTemplate.wiki
_Index.wiki _TocItemTemplate.wiki
_PathBodyTemplate.wiki _TocVersionBodyTemplate.wiki
_PathItemTemplate.wiki _TocVersionItemTemplate.wiki
_PathSeparator.wiki _VersionIndex.wiki
_SideBar.wiki _VersionTemplate.wiki
_Template.wiki _VersionTitleBar.wiki
_TemplateStyles.wiki

So what else do I have to do to activate the doucment feature?
Any help is very appreciated.
Thanks

Martin