Unplug the machine.
Fill the water tank, and drip a little water into the out-spout to prime the pump.

The auto-off feature is designed to protect the pump from running dry and burning out.
*Some models had a reset button on the rear, if yours has it then use it.

Plug the machine back in and give it a try...once the pump sensor acknowledges water, it will reset.

***Don't forget to VOTE for the guys who take an interest in helping!