Premia 9 alarm - error 77, manual does not identify what this means, help?

My Premia 9 alarm keypad is displaying 77 which I assume is an error code. The user manual, system guide manual, and installation manual do not identify what this erorr means. None of the buttons on the keypad are working, I cannot clear the code. The light on the alarm box outside is flashing.

Can anyone point out the cause?

Thanks