If the Mac version here :
https://www.ootpdevelopments.com/ootp-prior-version/
is wonky, try the one here:
http://www.ootpdevfiles.com/ootp/
The Mac file should be near the top with a dmg extension. There is a trick to getting around the gray. I can't find it atm. It may be that you start a16 game, then come back to the 16 Start screen? I'll keep looking if no one else helps. I don't have a Mac so tough to replicate on my end to assist.