I need help getting my UR22 and New iMac Working

Same issue here using GarageBand on Mavericks (10.9). It work just fine at the beginning but then keeps freezing with error msg mentioned in the initial post.
I applied the latest driver and that does not seem to help, too.
This is annoying. I think I’ll return the device as I’m not sure there will be a fix on this in the near future.