Oh, that is sad.
Are you still using very same USB interface that you have used with Windows computer?
I am not sure why it is happening, but you can at least try another driver for USB interface:
You can download it here:
https://www.silabs.com/documents/public ... Driver.zipWhen you start the Spirit Settings, are you then able to see a Device in the Connection tab? This is very important, if there is no Device, then it can't work and it mean that installed driver in Mac does not work.
In completely worst case there are options:
a) To get Wifi-Link which will replace USB interface and all the settings can be done wirelessly. In this case no driver is required so it should be basically Plug & Play.
b) To try the Spirit Settings in something like Parallels, VirtualBox while running virtualized OS such as Windows or Linux.