The interior temperature of my refrigerator unit is 45 degrees and the message CE is present. My Sub Zero manual says the service light may be flashing if one or more of the zones run too long or there is a faulty temperature sensor. It suggests turning the unit off with the on/off and then restarting--which I did. I still get the same message.
Also, he fridge door seems to be slightly out of alignment although it seems to be sealing when closed (but perhaps not enough!) Could readjusting the door be the solution?

Refrigerators - Sub-Zero - 632 / S