Üdvözlünk a GTA5-Mods.com-on

Hi Vrinity, i've been trying to mod in my own mask but i'm having difficulty. It's a dragon full helm from Runescape. I've extracted it from the game's cache, converted it into a 3ds format and I followed the guide you are linking. I get to the point where you have to do the cmd command and it says the following error - https://gyazo.com/f77fe8be231c0a80fa1ff13720bf9655

Not sure if this is to do with it, but each part of the model has it's own colour, there's no texture - https://gyazo.com/397427335d4b803a597eee43e7feb4df

Also, the guide doesn't seem to get to the point of creating a .ydr file. Could you somehow help me? Thanks :)