Stuck Pocket Door
I use a Johnson Door track and out of perhaps a huundred or so, I had one of them disconnect. It is not possible for them to jump track because they have a triple trolley wheel contained within the track system.
Is it possible for you to lift the door to slide it out? You might need to use a screw to run intop the end of the door to use as a handle. Once out, it would be easier to figure out.
Was the door getting hard to open and close at any time, like it was too big for the opening? If it was, it may be moisture has expanded the door and it's too big for the 'slot' (that might have been constructed with too little tolerance). That could end up being an on-going problem unless the 'slot' is enlarged a little where the binding occurs.