Add the Ba2 to your archive load list. If Updating, delete "InvisibleBackpacks - Materials.ba2" and "InvisibleBackpacks - Textures.ba2". Also remove those lines from your load list.

Add InvisibleBackpacks - Materials.ba2 and InvisibleBackpacks - Textures.ba2 to your archive load list. This uses materials and textures instead of meshes. Should allow skins for the base backpacks to work properly.

Loose Files for Use with Baka. If Updating: remove everything in "Materials\Backpacks\..." and "Textures\Backpacks\..." folders.

This uses materials and textures instead of meshes. Should allow skins for the base backpacks to work properly.