Is this a background image or did you change the color of the background? If you changed the color of the background and then moved that layer up, it may interfere with seeing layers beneath it.
Otherwise, my thoughts are:
a) make sure your tilemaps are visible
b) make sure your tilemaps are have a z order higher than the background image
c) If your tilemaps are on a different layer, make sure that layer is higher than the one with the background image
d) If your tilemaps are on another layer, make sure the parallax for that layer is set appropriately (things can really end up all over the place if the parallax isn't set up correctly)