a manual sync from the client library manager fails saying that auth permission id and passwords must be set on the server.
G'Day Bill,
The above quoted text is the issue, and it isn't the Windows UserID and Password that needs to be fixed, which it sounds like is what you did.
You need to redo the MC Media Network Authentication setup, and the MC Client needs to be forced to log in to the MC Server again.
1. Shut down the MC Client
2. On the MC Server, go to "Options > Media Network" and untick the "Authentication" setting.
3. Close MC on the Server, wait a minute, then restart MC on the Server.
4. Go back to "Options > Media Network" and tick the "Authentication" setting, then enter a Username and Password to be used on all Clients in future. The Username could be the same as what you already had, but the Password should probably be new.
5. Make sure that "Read-only Authentication" is Disabled.
6. Start the MC Client and try to connect to the MC Server (load the Server Library). You should be prompted for the Username and Password that you just added to Authentication in the MC Server.
That should be all that is required, as long as all the other sync settings are correct. i.e. On the Client, "Options > Media Network > Client Options > Auto sync with server" should be ticked.
If the MC Client doesn't ask for a Username and Password at step 6.;
Go to "Options > General Advanced > Reset all confirmation messages", then restart MC on the Client and try again.
If that still doesn't work;
Go to "Options > General Advanced > Reset reset saved internet passwords", then restart MC on the Client and try again.
Let us know how that goes, and at which stage it worked.