I suspect you're correct, since I have no problem with Zorro on another Windows 10 machine.

But both are my own machines, and in both cases, I have admin logins but normally run as a standard user. I've never encountered anything like this except when trying to run Zorro on this one machine.

That reminds me, during installation, you are asked to enter your name. Is there any significance to what you enter in that field? Could my issue be related to that?