Render problems with the latest version of rhino for mac

I have some problems with the latest version of Rhino downloaded lately. When I try to render or to view the object in shade view, the render produces only some basic shape, as the image shows (and the shade view doesn’t show me anything other than the plan). Any solution to solve this problem? Thank you!

Can you post an example file, please?

well, there is a photo with a grey background and one white stripe. I’m posting it again. and the previous photo is the wireframe view of the same polysurface

post the .3dm

Yes, sorry. Please post the model. The screen capture does not give us enough information.