Stuck in "Preparing global light manager"

Hi

I have a strange problem, which is the same both in Rhino4 and Rhino5. Everytime I try to render my file it stucks in “Preparing global light manager”. The strange thing is that if I copy the file into nre opened Rhino file. It works fine, but only the first time.

I’ve tried to reinstall rhino + vray, and formatted my computer, but the problem is still there.

RT

I found that the RT was enabled, and that was the reason.