Neither can I. They all worked before an update this spring or summer.
I even bought a new monitor and plugged it in as instructed with three cables. It still doesn’t work.
Yeah. Topaz is now a dud. Sad. I’ve been a customer for a long time.
I was with them from the very first stuff they put out. V1 of most products. For my photography, I mostly used denoise and sharpen. The new AI versions were slow but did an incredible job. Those were pretty great when I needed them. Since they don’t work for me now, I have started investigating On1. Denoise is not as complete, but serviceable. It at least works on my PC.