Maybe I didn't ask the right question.
What happens is that Wondershare Video Converter keeps disappearing (the executable cannot be found). I assumed that Avast was deleting it, or hiding it. I've reinstalled it maybe 15 times. I can use it for a couple of sessions, and then it's gone again.
I just re-installed it again, found the executable, right-clicked on it. I turned On "Always run in Sandbox" and then turned it Off again. I ran an Avast scan on it, and Avast had no problems.
Dunno... I'll report back again if it disappears again.
Clark