Here are the most common reasons for this to happen:
Broken Garage Door Spring
Residential garage doors can weigh anywhere from 100lbs to 1000lbs. It is not the motor, like some assume, that is lifting all this weight to open the garage door. The weight of the garage door is counterbalanced by the tension of the torsion springs (usually located above the door). If the spring is broken, or the incorrect size, the door will be difficult or impossible to open by hand or with the opener.
Binding Track or Hardware
There are many moving parts on the garage door (hinges, rollers, cables, drums, top and bottom brackets, drums, bearing plates). These components allow the door to open and close smoothly with the help of the springs. The track is fixed in place and act as a guide as the overhead garage door travels from the closed (vertical) position to the open (horizontal position). If one of these parts fatigue and break or become loose it can cause the door to bind. If one of these parts were installed incorrectly it can also lead to excessive friction. It is also important for the track to be properly secured and installed level and plumb. Loose track or uneven track can cause issues
Broken Garage Door Spring
Residential garage doors can weigh anywhere from 100lbs to 1000lbs. It is not the motor, like some assume, that is lifting all this weight to open the garage door. The weight of the garage door is counterbalanced by the tension of the torsion springs (usually located above the door). If the spring is broken, or the incorrect size, the door will be difficult or impossible to open by hand or with the opener.