Materials not rendering

[lfmicolta]

Hello,
I just got V-ray for rhino V.3, I have downloaded some of the materials offered in this site but i can not render them. The items display either completely black or an error displays "invalid material". How do I get this materials to work properly?

Thank you.

[Nuder]

Re: Materials not rendering

if once the material is loaded, than try to check if the directory for the file is adjusted.