Fyi: if you can't access material settings try this

[JakeL]

I couldn't access any Vray material settings but narrowed it down to a plugin conflict.

The culprit: Spline patch (motion gimmick).
I don't know whether the one buried in my plugin folder was the current version, but deleting it fixed the problem.

/J

[dagmar]

No problems known with any of our plugins and Vray.

Splinepatch is from Heyne-Multimedia

best wishes
dagmar

[JakeL]

Actually, it was the MG (not Heyne) "spline suface B" , but it could have been an old version.