Missing root material (Creation Kit warning)

[Macrophobic]

I found an interesting mod, a mashup of engineer armor and utility coveralls. I'm using a lot of mods and I don't want to exceed the limit, so I just wanted to use the meshes or edit the .esp file to add some material swaps (using retextures of Sturgess' outfit and a vanilla texture of Teagan's armor). When I open Armor Addon/Model Data dialog and change the .nif file path or material swaps, I get an error:

 

 

MODELS: Missing root material: Cloth_R_C_02.

MODELS: Missing root material: SturgessTorso_0.

MODELS: Missing root material: RLeg_Calf.

MODELS: Missing root material: Spine1_skin.

 

 

Female version is similar

 

 

MODELS: Missing root material: Spine1_skin.

MODELS: Missing root material: FScribeGloves_1.

MODELS: Missing root material: Neck1_skin.

MODELS: Missing root material: Spine1_skin.

 

It's not just a warning I can ignore - it somehow prevents me from saving, next time I open the file the changes are undone and I'm not sure if the file is not corrupt now.

 

Is there a way to fix it? Or maybe there is some other, similar mod I missed? The idea of merging these outfits is great and I could even add Sturgess' belt and goggles and his tools would be placed lmost exactly inside the vest's pocket, only goggles clip a little.