Step 1: Open a support case.
Some things to collect:
/var/log/visualrf/visualrf.log
site.xml -> navigate into VRF to a map where you had placed APs, left click on the map section so that it's the active frame, keypress ctrl+x+m+l. This should launch a new tab showing a text representation of your map. See if you can search for the AP names that you've previously placed. If you see it in the XML, then it's possible that it's just a display issue - stopping and then starting the VRF engine from the VisualRF Setup page should do the trick.
If for any reason the APs are not showing up in the site.xml, then a support case is the best way to debug. Do not restart VRF if this is the case.