When LISTSERV starts it sends the command "fsav /version" (Windows) or "fsav --version" (Linux) to FSAV.  If there is a problem with the response, LISTSERV's AV scan feature will be disabled.

You must also have current paid maintenance for the AV scan feature to work. This means that for sites with perpetual (non-expiring) Product LAKs, an additional Maintenance LAK must be installed.  (For sites with non-perpetual Product LAKs, your maintenance expires at the same time as your Product LAK.)  To check your maintenance status, issue a SHOW LICENSE command to LISTSERV. There should be a line in the response that looks like this:

       Maintenance until: 26 Nov 2018, serial number MNT-EXAMPLE-1

If the SHOW LICENSE output says

       Maintenance until: No maintenance information

either your maintenance has expired or you have not received or applied your maintenance LAK.  If you need a new maintenance LAK, please contact your L-Soft sales representative.  (The support department cannot issue LAKs.)

If maintenance is current, try another stop/start of LISTSERV.