Are you sure that the software closed by itself? How many times you have tested CAS firmware before, I bet it has never happened before.
Before you do anything, check laptop USB, check your usb cable, and the WVCI usb connector too.
After you are sure all are OK, you can let Autohex II communicate with the CAS/FRM by waking up the car! for example, open the door, close it, then start testing.