After activating an Antivirus subscription for the Content Analysis System, it still displays as unavailable in the Management Console.
When you link an AntiVirus to the appliance, it does not show in the license key file. Instead it goes through another service called the subscription service.
To enable the subscribed Antivirus service, force a re-check of the license:
If the problem persists, a Technical Case should be opened with Blue Coat Technical Support for further investigation.