Workgroup Manager: Sharing is Greyed Out

Having re-built a 10.4.11 Server OS, migrated data from the old drives onto the new ones, installed users, got it up and running, I now find I have a problem where the Sharing icon on the Workgroup Manager is greyed out, and thus I can't get into it to adjust sharing settings, add things, etc.

Currently, users seem to be able to mount all the shared volumes, because they were setup before this issue started, and I turned up the ACL's as well. However, I'm concerned I won't be able to make changes or updates. Is there something I've done or missed that's caused the Sharing to suddenly become greyed out and inaccessaible from Workgroup Manager? And more importantly, is there a way to correct the issue?

Thanks in advance for your insight!