Not able to use Rhino6 render

I try to assign materials for rhino rendering, but there is no window showing up. I also tried to click render, but nothing pops out. The command line just showed that the render time is 0s. Also, the command just said unknown command: showpanel = toggle when I clicked the material editor from top bar.

Hello - please try running the installer again and choose ‘repair’ . If that does not help, please run the SystemInfo command in Rhino and post the full results here.