I am a jack of all trades. I found out that some times you need to oil or grease the rollers and the opener for the track. Make sure that the sensor is not mounted to the track; If you have a jolt or jump on the door moving, It will trip the sensor. Make sure they are level and no cobwebs in the way. If the door is not closing smooth or stright and the sensor is connected to any movement, it will trip. I had a friend with the same problem for two years. I fixed it in 10 min. Thats 3 years ago. I hope this was helpfull to you.