Cubase 10 crash on startup OSX

As the description says… I can’t get past the start up screen it keeps crashing.
I’m using an iMac (Retina 5K, 27-inch, Late 2015) running OSX 10.12.6, I have been using 9.5 and Cubase 9.5 still starts up for me.
Cubase 10 worked for 2 days after I first installed it, but no longer starts up.
I’m trying to locate the crash dump files in OSX (any ideas where that is?)
I’m also trying to start it with preferences disabled, but not sure how…
thanks for any advice,

I think I have narrowed down my issue:

When I unplug the USB interface - a Behringer FirePower FCA1616 , Cubase 10 starts up
Maybe it’s time to update some old hardware??