Booting from 'Live' USB with a Mac Book

I have both “live” DVD and USB, supplied by a well known US supplier.
When I try to boot from them I get the caption ‘the disc cannot be read.’
I think I realise that I am missing something and/or doing (or failing to do) something really fundamentally naive or stupid.
There must be many using an OpenSuSE live USB on a mac - can anyone help, please?

Regards, lim

We’ll need a few details to get things going;

  • What Macbook? Pro? Which Year/Model?
  • What openSUSE version?
  • Have you tried booting the said installation mediums on another machine?

The machine is a MacBook Pro Retina, 13 inch, Late 2013.
The Live USB is the latest version, I think that’s 13.1
I only have the rMBP, so no other machine to try it on

Regards, lim