1. RDP to the Harvester, open a command prompt, and run:
2. Then run the following using the IP address of the missing device in place of x.x.x.x
update routers set updatedon=unix_timestamp() where address='x.x.x.x';
update persistent_map set updatedon=unix_timestamp() where routerid in (select id from routers where address='x.x.x.x');
3. Recycle the "CA NFA Harvester" service and the "CA NFA Collection and Poller Web Service".
4. Check the Admin->Enable interfaces page again and see if the device shows up, note that it may take up to 15 minutes for the device to show up on the Enable interfaces screen. Once its there it will need some time to license the interface and start displaying data.