Garage door not closing properly.

[bawbster]

Got in from work last night and noticed the garage door wasn't shut propely zfter wife was in it earlier, managed to close it but it was tight and the door was rubbing against the frame on the right (looking from outside).
Had a look this morning and after openimg and closing a few times it got worse. Now the bottom right hits the ground and it doesn't close. When it's opened the runners are at different heights, 2mtr for the left and 1.9mtr for the right.
Took a few photos.

Any suggestions please.

 

[just pumps]

Total stab in the dark but has a wheel jumped a notch/cog allowing one side to be lower or has a wire jumped off a pulley. Pulley no longer fixed somewhere.

 

[bawbster]

Total stab in the dark but has a wheel jumped a notch/cog allowing one side to be lower or has a wire jumped off a pulley. Pulley no longer fixed somewhere.

The image here shows that the wire is not in the groove like the other side could that be it?
*edit* Put the wire back in the groove and that's not it.

 

[just pumps]

Sorry but cant make out from that photo however both sides should be the same and any works is easier to do when the door is down - Be careful of trapping fingers under wire!

 

[crank39]

My first thoughts were the cable has jumped out of its groove in runs in as you open, I still think thats what it'll be, stand inside and close the door and the cable should unwind the drum and when the door is closed there will probably be a quarter of the drum with cable on it, now make sure on both sides the cable starts in the first availble groove(I know its a continuous groove), it possible its jumped a full turn and ended up in the nxt groove, this can be seen when its fully open and one side is lower than the other

 

[bawbster]

Got it sorted, turns out a circlip came off one of the arms and that was the major problem, cable was also off a groove and has a kink in it now, so will have to get that replaced at some point.