OS X 10.9 Mavericks and Cubase 7

Had my first full on crash today.
Had a project open for around 8 hours today and suddenly I got a white screen and some text saying the Mac has crashed.
It rebooted.
Loaded up cubase but Cubase crashed every single time I tried to “open file…”
It would crash as soon as I opened my self made directory “Cubase Projects”
I tried it a few times, crash crash crash.
In the end I think I just found the project file and double clicked it and got in that way.

I had to turn on and off the UR28M as I think it crashed and wasn’t being recognised.
Infact it was in the device list under Yamaha something…

The crash happened when I was switching the device driver over from UR28M to Built In Audio on my iMac.
I did have a deactivated and turned off DSP effect on one channel and thought that might have been the cause.