Sorry for the late reply! Did you follow the guide in the spine-unity documentation page? Most of the time it's just that the file extensions are named incorrectly, they have to be .atlas.txt and .skel.bytes for Unity.
If you are sure everything is named correctly: could you please attach the problematic three exported assets to this forum thread, then we can have a look at it. You could also send it as a zip package to contact@esotericsoftware.com (mentioning this forum thread URL for reference) if you prefer.
