I’m a newbie to SketchUp. I’ve completed my designs, and downloaded the Vray demo for rendering, but I can’t ‘find’ it. How do I get Vray to work as an extension? SketchUp doesn’t recognise that I’ve downloaded it, as far as I can tell.
seems to be a common problem with the recent V-Ray 3 ßeta Version required for SU v2017, would check with Chaosgroup why this happens and when the 3.0 final will be released.
Did you check this help manual for Vray setup and installation?
Vray version is not stated, but considering the current beta version (v3) does not have demo. Therefore I suppose OP is trying to use v2.0 demo with SketchUp 2017. And as @sketch3d_de has stated, V-Ray 3 beta is the only version working with SketchUp 2017. Perhaps revert back to SketchUp 2016 for the time you are using the demo.