First, thanks for updating the mod for 0.15 - I've been missing it for a while!
For some reason the mod zip contains a copy of both 1.2.1 and 1.2.2, so the game won't recognize either. Also the folder name in one of the 1.2.2 json files (?) is wrong, which means the game won't load the .png files.
(If you try to download it via the in-game mod installer, you'll see what I mean.)