Rear passenger door

Evening all. For some strange reason my rear door n/s has decided it doesn't want to unlock when I press the button on key fob. Also when I try from the button inside of the car. All other doors unlock and the boot just not that door. I did notice it was making a funny noise the other day from that particular door but it would still unlock but now it doesn't want to, And when I unlock it by pulling the handle from inside and press the button it locks but won't unlock when I press unlock...

Edited 11 January, 201511 yr by keithys