TypeError: Cannot read property 'split' of undefined

[Heimdallionaire]

Unable to nest folders without 'TypeError'. With basic folder structure, Type folders only, it runs fine but as soon as the imagers are put into a folder inside, it errors. Have tested with/without spaces, #'s, and isolated to single image. Also tried recreating the example from README docs (Common#70 & Rare#30 folders)
Works:
|__Background
--|__BG1.png
--|__BG2.png
|__Outfit
--|__jacket1#50.png
--|__jacket2#50.png

Doesn't Work:
|__Background Layer Folder
--|__BG1.png
--|__BG2.png
|__Outfit Layer Folder
--|__Outfit Layer subfolder
----|__jacket1#50.png
----|__jacket2#50.png