Export error

[Tomori9n]

keep getting this errror when trying to export the "Hyakka wa Gekka ni Chirinuru wo" model, it only exports the head textures but not the body
https://files.catbox.moe/e1g6mh.PNG
https://files.catbox.moe/wnsd19.txt

[hozuki]

This model body uses a material lambert which is... well, basic Lambert material. The corresponding part of the mesh is the inner collar. (But this part is totally invisible... another mistake?)
It has a _MainTex parameter but that parameter does not reference any texture (it is a null pptr). So by default it should be using the "white" texture. Fixed in the next commit.