Strange. Maybe it's like the mane glitch.
Try clicking Angel Wings and then back to Bat Wings. Or take them off entirely and then re-equip?
If you haven't already, that is.
Then, it might be a glitch with your exporter, to which I'd suggest moving the preset to a different number, renaming the files to that number, then open the material in notepad and press Ctrl + H, then have it replace _12 with _9(or whatever other number you choose).
If still, it does not work, then you may consider reinstalling FeralHeart.