IndexError while exporting

[ZarimSF]

Hello,
most files work just fine but with a couple I noticed an Error while exporting:

Traceback (most recent call last):
  File "C:\path\to\scripts\addons\export_static_msb.py", line 212, in execute
    if SaveMSBStatic(context, self.filepath) == 0:
  File "C:\path\to\scripts\addons\export_static_msb.py", line 80, in SaveMSBStatic
    triangles_per_material[p.material_index].append([mesh.loops[i*3+0].vertex_index, mesh.loops[i*3+2].vertex_index, mesh.loops[i*3+1].vertex_index, i*3+0, i*3+2, i*3+1])
IndexError: list index out of range

location: <unknown location>:-1

bpy.ops.export.msb_static(filepath="C:\\path\\modelname.msb")

I did not change anything with the model, just used import_static_msb and directly exported with export_static_msb.py.
This happens for at least the following files:

• figure_hero_female_head_blond_ponytail
• figure_hero_female_head_ponytail_black
• figure_hero_female_head_ponytail_black2
• figure_hero_female_head_red_ponytail

(yea, seems to have a problem with ponytails :D)

Maybe anyone has an idea?
Thanks in advance