Vray rendering went black (except for the sky) - please help!


Hello to everyone.

I’m making an exterior scene for my portfolio with sketchup ver2013, and I stuck with a problem occurred yesterday.
So, my rendering scene went all black except for the sky bit. (Rendering was all fine till the day before yesterday!)
I tried few things ; 1. chaged visopt in case if I’m having a wrong option.
2. tried re-importing material if vray material is making problem.
3. rendered a normal box in another sketchup file but it went absolutely fine, it’s just this file that went wrong.

Can someone please help me to fix this file? I need few scenes in an urgent matter… :frowning:

Thank you!