"model texture path suffix" is the Very last setting on your Options page.
is this your doing, a new HP for a ship? if so you do need to re-export.
I my experense as you open the Nif, then load the HP, it should say noname in your right menu [at least that has been the way it has happened for every GOOD ship\nif\model] , but everyopne I ever gotten without noname has never worked well and I had to send it back, to get redone.