After a long ride on some bumpy roads today I found that the seat wouldnt unlock, the key was turning and the lock action felt normal but the seat wouldnt release, I released the seat by putting my hand under the plastic panel just behind the key lock feeling for the cable and then pulling it to pop the lock.
Once open I removed the black inner tub, this gave me access to the rear of the key lock where I found that the cable had jumped out of the slot in its clip (see first photo) removing the tub requires undoing 4 bolts, and it is probably easier if you first take off the seat unit, I also removed the power cables from the main isolator switch, and after lifting the tub up slightly I also disconnected the 2 charger port wires at their connector plugs, this enabled me to remove the tub completely out of the way, but it is possible to leave all the cables connected and squeeze a hand in if you have someone to hold the tub up.
After clipping the lock cable back in I fitted a cable tie around it to prevent it coming out again (see second photo)
With small hands and nimble fingers would also be possible to re-fit the lock cable from underneath the panel if you laid the scooter over on its right side or had someone to hold it leant over, this would save undoing anything or using any tools.
Hope this helps if you havent already had his problem and figured out the fix.
From Paul IOM