Another Door Problem

[Newspaperman]

Had problems today with the nearside sliding door it would not open from inside using the push button and the hook latch at the bottom does not move now from either the handle outside or the button. Had a quick look the bottom mechanism is operated from a cable that pulls the hook mechanism. It used to as last week I lubricated the mechanism and tested it.
Im thinking now is door card off and look for the cable to see a problem exists any ideas?