One problem related to engine shut off without warning has been reported for the 2015 Nissan Versa. The most recently reported issues are listed below.
My car shut off while I was stopped at a stop sign. The radio and air were still on. The car would not move. In order for me to move the vehicle, I had to put it into park, turn the ignition switch to off and turn the ignition back to on. Basically turn it all the way off and restart the vehicle.