Well, it was just a chair/computer interface problem...
My VST folder path is not the default path. I forgot that the UAD installer does not use custom paths. So when I updated my UAD plugs, I did not notice any problem in Cubase because the default folder is in the Steinberg folder.
The plugins kept appearing in Reaper but were nonexistent.
A simple clear cache/rescan dealt with the problem.
Going back under my rock now.