a blank status shows when there is no Anti-Virus version information available (normally signifies that either SAVXP is not or not correctly installed). Unknown means that the endpoint reported a combination of SAV version, Virus data version, and list of IDEs that isn't know to SEC. This could be because the endpoint hasn't updated for a long time, reported only a partial version information, or during an update one or more IDEs have been "left over". The latter should correct itself with the next actual update - others are likely cause by a failed update of SAVXP.
as most issues are likely caused by a failed update or corrupt installation a reinstall/reprotect should take care of a number of them. For some this might fail and these case have to be investigated by checking the install and uninstall logs.
