I downloaded Slate Digital Virtual Mix Rack because I would like to try their free compressor, The Monster.  I have an iLok3, so I installed the Virtual Mix Rack software and selected The Monster option, got my license key, and activated it through the iLok software to my iLok3 dongle.  I then ran the Cakewalk Plug-In Manager and performed a scan, but I can't find either the Virtual Mix Rack or The Monster listed in "Registered Plug-ins".  
 
Do you have the Slate Digital Virtual Mix Rack installed?  If so, how does it appear in your list of plug-ins?

Yep. Check if you have not active your plugin customized layout. It is not updated by new installed plugins. You could also force full rescan and check in plugin manager (sometime because of some bug there are cases plugins are there but not listed in browser ). If after rescan still not in browser but seen in plugin manager you could create your layout and add there. I was forced to do such 'trick' in few cases (massive amount of plugins - mess but no time and strength to clean it up).

You will not (IIRC, not at the DAW right now) see the Monster anywhere as a VST because it can only run in the VMR.
 
Why you can't see the VMR has probably been covered by Piotr.

Also, in the browser, set the instruments menu to display by manufacturer. IIRC, the default configuration didn't display a bunch of my plugins.

Bapu is correct - you won't see Monster as a VST, just the VMR.
 
 
 

Thanks all, I was actually able to find it with the old "cut and paste the .dll/.vst3 file to another directory, scan plug-ins, copy it back to the directory, and scan again, and wow, it appeared listed as a .VST3.  Remember that trick going forward when you can't find a plug-in you installed.