Attempting to update from 10.2.1 to 10.3 and then 10.3.1 in a single server envoronment using embedded Sybase db on Windows 2008, but can't get even get started since agent on primary server will not log in and can't be refreshed from the ZCC. When attempting to log in on the server to either the AD realm or the Zen Realm, I receive the following:

Unable to log into the ZENworks realm because the system has disconnected from the network and the specified credentials did not match with the credentials cached on the system.
- You must specify the credentials used to previously log into the ZENworks realm from this system
- If your credentials have changed since the last login, you must reconnect the system to the network to be able to log into the ZENworks realm.
Note: Repeated unsuccessful attempst might clear the cache and prevent you from logging into the ZENworks realm.

User source is fine, ZCC says agent on the server is fine, all workstations can log in just fine and have been able to for a long time, obviously I can log into the ZCC, etc. Last server contact date on the server agent is May of 2009, but the contact date and refresh date on all workstations is current.

Hoping there's an easy fix for this, but I'm treading lightly since it's a single server and workstations are still working fine.