I seem to be having the exact same problem as in this post: http://esotericsoftware.com/forum/Failing-to-import-into-Unity-4513
I attempted to follow the steps for "Drag and Drop Import" shown at same URL. After step 1 (drag folder to assets directory) it starts an import process in Unity. But the import fails with "Skeleton JSON Import Error! Could not find matching AtlasAsset for skeleton". I looked in the directory
all the expected PNGs are there and loaded as sprite type. There is a new "skeleton_SkeletonData" object
clicking on it shows several messages like "Missing region: 'innertube_water_test0001'".
However in my case, the atlas is correctly named with the ".atlas.txt" extension, and I'm still having the same problem. I captured a quick video demonstrating it here:
(sorry the links aren't formatted properly, I'm not sure how to do that in this editor)
Any about idea what's going on?