Just got off the phone from one of the rep's of Chamberlain...Go to the sensor that is blinking(it should be the one with the green light) loosen the sensor until the light goes out, then tighten it back up until the light come back on, and push the garage door opener. it should reset the unit.

Either the eyes are seeing something as the door is closing or you need to reset the down limit tension inside the left lense cover