Garage door DIY fix- was stopping and reversing on the down stroke.

My garage door has not been closing…it stops before coming all the way down and reverses direction going back up. It’s been doing this for a week and has to be helped down to get it closed. The weather has been cold this past week and i just got around to fixing it today. Note: This is a screw drive opener with a geared trolly that interfaces with the screw drive.