For anyone still having issues with PS CC & On1

I was unable to use the On1 plugins with the new version of PS. I
tried everything imaginable, including reinstalling PS & On1, and more
than once. I kept getting a "Disk Error" message in PS.

I was opening PS from the Creative Cloud window. On the suggestion of
On1, I found the executable in the CC folder under Program Files, and
opened PS from there, and everything works fine now - at least as long
as I open from the executable.

I have no idea why this works, but if you are having problems, try it.