My door won’t close and the lights on the opener blink off and on.

The infrared safety sensors are out of alignment, obstructed or faulty. The sensors are located about a foot up from the bottom of the track on either side of the door. Both lights should be solid. Check to make sure that they have not been knocked out of alignment or that the there is nothing in the way that would obstruct the beam. If the sensors do not operate properly you can the press and hold the wall switch until the door closes completely. If you are unable to remedy the situation please call a professional for help.