Combining 2 different armor sets

[Proximitus]

I'm the creator of the Lone Wanderer's Protection Kit, but since the armor addons don't take any damage and make you a bit invincible, I was thinking of making schematics.

 

So, for the first schematic, you need a vault suit and raider armor. At a workbench, you create the Lone Wanderers Vaultsuit MK I.

 

With the second schematic, you need the MK I, leather armor and combat armor, creating the MK II

 

With the third schematic, you need the MK II and the armored vault suit to create the MK III.

 

This way, you get 1 piece of armor, that uses the upperbody biped model, instead of 6 different files.

 

The problem is, when I load up the vaultsuit.nif in 3dsmax, add the left leg armored pads (the one from the raiders armor), and try to export it, it keeps giving me a warning that I need to specify 1 bonenode.

 

Can someone tell me what this error is and how to fix it?