It took me awhile, but I have finally found my problem. I was not aware that the 'Face' image needed to be tied to the 'Body' image in the Face category, so I only had 1 body image index in the body folder. When the plugin was trying to open the scene, i have a total of 7 face images in the head folder but the body folder only contained 1 body image so face index 1 was throwing the error because there was no body index 1. After everything else I've looked at a tried comparing my setup to your folder structure and file naming, in the end just adding 6 more body indexes for face, walk, and battler eliminated the error.
Thanks for everything, I look forward to getting my ideas with this plugin up and running!
- Dejil