DIAGNOSIS The flashing light means the machine has hit its automatic cleaning reminder timer (usually after something like 24-48 hours of total operation). It won't make ice until you acknowledge and complete the cleaning cycle.
FIX With the machine ON, press and hold the "Clean" button for 3 seconds. The light should switch from flashing to solid. The machine will then run its internal cleaning cycle for about 5-7 minutes, pumping water and vinegar solution through the system. You need to have the reservoir filled with a cleaning mix ( specifies a vinegar ratio).
IF THAT DIDN'T WORK If holding the button doesn't change the light, unplug the machine for a full minute. Plug it back in and try the hold-sequence again. A full power reset can clear a glitched reminder.
HEADS UP Don't just ignore the solid cleaning light after you start the cycle. Let it run to completion, then do an extra rinse cycle with fresh water to get all the vinegar out, or your next batch of ice will taste like salad.