Hello Dave,
This is not a database error, it was programmed like that.
You should use a server package to open this database, and then connect with clients.
Please, check on standardinstall.com, if there is a suitable server package available (you might find it in Older Versions) - make sure the dated version of the server and client are the same.
You can also test on 8.0 client single-user installation, it should be possible in 8.0 again.
HansaWorld Support Team