Updating the iLOK manager is a good place to start but sometimes you just need to rebuild the entire plugin cache & do a complete rescan of the system.
If you want to do this - and it’s a hassle, but I believe to be a worthwhile one, then first back up all your prefs & put them somewhere safe. Now delete the VSTPlugInfo.xml file and the VSTPlugInfo2.xml file from your prefs, as well as the VST2 blacklist.
Relaunch, and only the basic locations will be scanned. Go into the plugin information window next & point to all of your VST2 plugin folders you want to be available (or check to make sure they are there). Do not mix up 32 and 64bit versions of the same plugins - if in any doubt at all only point to 64-bit plugin folders & see what is missing you cannot live without first.