please contact support@chaosgroup.com about this issue. We would need more information in order to help. For example: the version of SketchUp, version of V-Ray for SketchUp you have installed, version of V-Ray for SketchUp you have a license for (double check you have the correct version installed for your license), Operating System, when did the issue first happen, what did you do just before this issue first occurred. Feel free to continue this thread, but I highly suggest you contact our support department also.