Norton Antivirus 2006: Live update could not find an update file on the server....
I just got that myself tonight. If you click on the link that LiveUpdate provides for you, it takes you to a Symantec Support page that shows you how to remedy the problem. If you read through the steps, it eventually leads to reinstalling Norton Anti-Virus. So you can either wait and see if maybe it's just a screw-up on Symantec's end, follow Symantec's instructions for fixing the problem, or just re-install Norton AntiVirus like I did.
Side Note: After re-installing NAV, my "LiveUpdate" has now become "LiveUpdate Express" which apparently is LiveUpdate v2.6
EDIT: In case it matters, I got this error using NAV 2005, not 2006.
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