I have found a treasure map that leads to absolutely nowhere, it has no X on it either and simply shows a picture of the ocean. I believe it failed to locate a spot for the chest as you can see on attached picture there is no land. This gave me a treasure map called "Map #0" which doesn't actually lead anywhere. I am pretty sure this is not intended and in like 12 yrs that I played minecraft this is the first time I am reporting a bug as I felt like the game put a prank on me.