Hi Mark,
> I installed the Mac version. It asked me if I wanted to grant access to my Documents directory and I said "no".
That's odd. Glu makes no attempt to access your Documents folder so I'm not sure
why you're being asked to allow that. Which version of macOS are you using?
Anyway, here's a possible solution:
installing the glu-1.0-mac folder in a different location (should be ok anywhere you have
read/write access).
If you do manage to get Glu to start up, please run Samples/getdir.lua and send me the
resulting output. Maybe Apple has changed the default location for an app's data
(on my Catalina system it's /Users/myusername/Library/Application Support/Glu/).
Andrew