Subversion addon - cannot make repository

I downloaded the Subversion v1.7.4-rnx86-0.5.7 for my Ultra 2 Plus and it installed OK. I followed the instructions below given in the add-on page

svnadmin create /opt/subversion/<name_of_repo>
svn mkdir file://opt/subversion/<name_of_repo>/branches -m "Created branches"
svn mkdir file://opt/subversion/<name_of_repo>/tags -m "Created tags"
svn mkdir file://opt/subversion/<name_of_repo>/trunk -m "Created trunk"
chown -R admin:admin /opt/subversion/*

but when trying the second I got the following failure

surire:~# svn mkdir file://opt/subversion/RichLectora/branches -m "Created branches"
svn: E170000: Unable to connect to a repository at URL 'file://opt/subversion/RichLectora'
svn: E170000: Unable to open an ra_local session to URL
svn: E170000: Local URL 'file://opt/subversion/RichLectora' contains unsupported hostname

Google wasn't my friend in this case and my attempts to post at readynasxtras is pending review, so I wondered if anyone here knew what the problem was.

Anything obvious? I have radiator 4.2.22