Have used Discus since version 2. When I dragged the 4.21 update to Applications, it overwrote 4.20 then wouldn't open. Could not get 4.20 back.
After several download/install attempts (from different sources) I had to reinstall 4.12 from the disk.
The ART file is in the same folder. Tech support has responded but after a couple of attempts to fix the problem the comment was "Yes, that's strange. Log says it seems to be in a loop of some kind." Have not heard from them in two weeks. Anyone have a workaround?