Did you install Buster via the Apple App Store or did you download the code from GitHub? The installation process should roughly go like this:
1) Launch App store, search for Buster and install it. (It is a free app)
2) Plug the ThumbDV into a USB port on your Mac.
3) Launch Buster
Buster's default config should select the ThumbDV automatically. Like the NWDigital Site says, the necessary FTDI driver (which is a USB to serial port driver) is included with the MacOS installations. (At least for the last three, not sure before El Captain)
