Why suddenly my stereo system/remote control for the alarm/interior lights gone on 2004 Mitsubishi Endeavor

I searched for probable causes and it seems to be my computer, is it fixable?? How much does it cost to get a new one. For more details, on the display it shows "communication error" and the time always resets to 1:00 when I start the car.

Asked by for the 2004 Mitsubishi Endeavor