Winter is here and my garage door refuses to stay closed!!

my Sears craftsman 1/2 hp (model number 139.18874) garage door closes and opens fine with a remote. However, when i close the door via remote or the wall panel, the door goes down, hits the floor for a few seconds, and then comes back up.
Here is a video that may explain better: https://youtu.be/F5DQLjm5dxA
I’ve gone through the forums and have checked the following:
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[*]checked the 2 censors to make sure they are aligned and the green light is on,.

[*]I’ve cleaned everything around the sensors it to make sure there is no obstruction.

[*]I have also unplugged and plugged in the power to the motor

[*]I’ve played around with the up and down tension adjustments in the back

[*]I’ve tried holding the wall button to by-pass the sensor. The door still doesn’t stay down. Which makes me wonder if the issue is with the motor unit?

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I called a couple of repair guys and they both quoted me $150 to come check it out. I am hoping someone here can help from having this unexpected expense.

If the door goes the whole way to the floor and then reverses the issue is the travel limit setting not the safety sensors. A lot of times when the weather gets colder the garage floor can heave up a little so the opener senses this an reverses (with the opener thinking there's an object in the way).

Look in your opener manual for adjusting the Close Travel Limit. You'll want to back it off a little so the opener stops running just as it touches the floor.

hi, wanted to give everyone an update. The issue was indeed related the up/down distance setting as GDZone mentioned. 
. However, my up/down lever had somehow loosened from the opener so had to get some professional help to remove the box and fix it (i guess I could could have done that , but i was a bit concerned with getting electrocuted . Thankfully, the guy that came over to fix it was an honest guy and didn't charge me much. I'd definitely be calling him the next time there is an issue. I hope this will help someone else having the same issue.