There are several types of pocket door hardware. You might need a carpenter who is familiar with them to look at it. Sometimnes, it's a simple thing, but in general, if iit is the type that will let it fall off the track that easily, it is more than likely the cheaper track and should be replaced.

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.

Good luck.

Pocket doors, unless they're very old, hang from the trolley's above. And usually they're the last piece of the installation to go in. There should be two threaded posts attached to the top of the door which have an adjustment nut on each for levelling, lowering, and raising. If you can gain access to these with a crescent wrench, you might be able to lower the door and lift it off the trolleys and out of the opening.

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.

I have a pocket door that will only open half way. It feels like something is stopping it half way. I looked and it seems the only way to see what is stopping it is to break into the wall. I can not get to the upper part of the door without ripping out the wood frame. Any suggestions?