It does seem to be something related to the mesh. I took the green hood, made some changes to it and then tried to associate it with a different slot. No matter what slot I tried to use, it would only show up if I put it in the top hair slot. I found a workaround though. I wanted to try putting the hood into the headband slot so that hair would show up. Since the visor only uses the headband slot, in outfit studio I added the visor to the hood and then deleted most of its vertices except a few on the brim. I then export to an OBJ file and imported that into Blender. In Blender I merged the hood into the visor and re-exported. Back in outfit studio I deleted the remainder of the brim and it worked; the resulting NIF file showed up when equipped in the headband slot.
