I'm having the same issue with the same error code, textures work but the meshes do not. I'm trying to use it for a custom worldspace in Skyrim SE, running through MO2, I have nothing installed in Program Files x86, game and tools are in different folders. I have also set an output folder with -o, which works perfectly fine for the textures. Hoping either Wavejumper found what caused his problem or perhaps Sheson has some more ideas I could try?