Wasn't sure about posting here or in the Sonar forums, but it really deals with a third-party plugin.
 
So, I bought my fourth Antares plugin. I've been through the iLok process many times, and am thoroughly familiar with it. For some reason, however, the DAW only sees the plugin as having an expired license. The iLok License Manager says it's licensed and ready to roll. And it's also in the common files/VST3 folder.
 
I have a ticket in with Antares, holding my breath.

Have you tried the "rescan existing plugins" in preferences - vst settings ?
And you've made sure "C:\Program Files\Common Files\VST3" is in the VST scan path ?

Double- and triple-checked.

A few of us had issues with 32bit I lok plugins a while back. Go to the plugin properties window for the appropriate plugin in the manager and make sure the crossbox is selected for make plugin active.

1. It's 64-bit.
2. It doesn't even show up in Sonar's browser, so there's no crossbox to check.
 
EDIT: Seems that Sweetwater sent me the 32-bit version. Antares graciously gave me the 64-bit and it works as advertised.