@jgpittenger oh nooooooo.... I’d heard rumours that silver fx wasn’t going to be updated and might no longer be usable at some point this year... I’m really hoping that isn’t true, but now you’ve got me worried :(
Photoshop plugins should (in theory) work with whatever version after plugins were added. It might have just gotten uninstalled or something. If you have the installer you could try reinstalling it?
"If you downloaded CC PS 2017 through Adobe Cloud the older version is still on your computer. In my case I found older version at C:\Program Files\Adobe\Adobe Photoshop CC 2014\Plug-ins. Under Plug-ins you will find a google folder with all of the Nik plug ins. Drag that google file to C:\Program Files\Adobe\Adobe Photoshop CC 2017\Plug-ins. You now have Nik Software that works with PS 2017"
I usually access it from Lightroom. I am using Lightroom Classic and the Nik collection is still available. Though I am using the new Topaz Studio (not Topaz Labs) and it works similarly.
I found I couldn't use it as an independant programme anymore, but since signing up for Lightroom CC, I can use it within that programme. Photo - Edit in.........
Same problem, easily solved by downloading again the Nik Collection and installing it. It automatically loads as a plug-in in Photoshop CC and Lightroom.
"If you downloaded CC PS 2017 through Adobe Cloud the older version is still on your computer. In my case I found older version at C:\Program Files\Adobe\Adobe Photoshop CC 2014\Plug-ins. Under Plug-ins you will find a google folder with all of the Nik plug ins. Drag that google file to C:\Program Files\Adobe\Adobe Photoshop CC 2017\Plug-ins. You now have Nik Software that works with PS 2017"
Good luck.
https://www.dpreview.com/news/1675836798/dxo-acquires-nik-collection-from-google-and-will-continue-to-offer-it-for-free-for-now