After running this update through Waves Central for my purchased Wave products, the Waves plugin effects showed up in the plugin lists for Cakewalk and StudioOne v4.2. All could be inserted as an FX in Cakewalk without problem. But in StudioOne v4.2, there were some that would not initiate when I dragged them over from the Browser. Specifically the Scheps OmniChannel and the Masserati series would not initiate at all.
Updating Studio One to v4.3 did not change this behavior.
I had another episode with Waves when updated to v10 from v9, but in that episode, the plugins wouldn't even show up in the browser. so this behavior was a bit different.
Since those specific plugins would initiate in Cakewalk, I should have looked and made sure that they were indeed updated. But I didn't. Just for scientific purposes!
so, I went back to Waves Central and ran the 'Repair' option under the 'Install' tab. and then on a whim, I downloaded the Waves V9-V10 organizer from the Waves website, and ran it as administrator.
And as if almost by magic, all the Waves plugins not only show up in the Browser in Studio One v4.3, but they all initiate and work correctly when placed as an 'Insert.' So I am not sure which step was the definitive 'cure,' but either running the Organizer or re-installing fixed the issue.