Examine the garage door opener's manual to learn what the light flashing pattern means for your specific sort of door. Otherwise, since the door opens, it may strike the rail. Also, make sure it is not hitting anything when it comes down that could be causing it to reverse. Garage doors are highly complicated and are composed of a wide range of components that operate in an incredibly intricate way. They don't usually require a lot of lubrication. Ultimately, you shouldn't repair a garage door by yourself because it's dangerous. If you discover that your garage door is reversing before even hitting the floor then it may be possible that there's an issue with the close-force setting.