I've discovered that on OSX 10.11, El Capitan, that if you Edit Manually, to edit the bfguils.conf file, it introduces oddities that Jason falls over, and MacMiner refuses to start.
You MUST create and edit that file in vi, or vim as its often call…
Ok, its working.
Thanks a lot for the help.
I deleted all the old stuff, re-downloaded MacMiner - and set up the config file where it wanted it, and it's working with no strange errors.
[2016-05-15 09:51:19] Started bfgminer 5.4.2-unknown…
Ok, tried that. Sorry, no good. Tomorrow, I'll remove MacMiner completely from the system, including the Application Support directory stuff, clean it all up, then reboot, then reinstall it, and try again ;-) Very strange.