"OS Error 0" when trying to launch

[mishalunchbox]

When i try to launch Cave Quest 2, i get two errors: my computer (iMac OS 10.14.6) says "CaveQuest2MacSteam quit unexpectedly;" Steam says "Failed to start process for Cave Quest 2: OS Error 0."

On that "Steam - Error" popup, there's a link to the Steam Support site that contains information on what to do about "Update & installation issues."  Even though i'm not sure that's the problem i'm having, i tried everything under "Basic Troubleshooting" except "Change Download Region" and "Reinstall Steam."  Then i came here to see if i could find some help that better targeted my specific issue.

I really was looking forward to playing this game, as the first one stopped running on my computer two or three OS'es ago...