Render all white

Hi
I just grabbed the Berserker - Tyrannosaurus Rex 2 . All the textures look great in the preview but when I render it in iray everything is just white and the textures do not show up. I've rendered other models like this and also tried materials from other models in the series which work fine so I'm guessing its a material setting but after messing with them cannot figure out what.
Any ideas?
Cheers.
Update. just tried diffrent lighting and it seemed to work. with the Default iray lighting and some others it will not. seems some lights are stopping the textures rendering. Does anyone know whay this happens and can i fix it? never had it before.
Post edited by Artbyphil on