Kmgw9v wrote:
I experienced a very similar problem. Every time I tried to move an image from Lightroom to ON1 as a plug-in, I had to re-install ON 1. A friend fixed the problem for a while, but when I later upgraded to Catalina, the problem resurfaced along with many others.
I should have never upgraded from Mohave to Catalina. Since I did, I am having problems with both Lightroom and ON 1. I now have a mess that will take research to fix.
After a student of mine and other reports on UHH . I stayed with Mohave. I am also using ON1 2020. I should have added this to my previous answer.