White Blocks/Patches On Rhino Render Image

This is the first time I’ve had this issue, but there are white blocks that appear on my image when I render it through Rhino. Is this a bug, or some kind of setting I need to manipulate?

Please post the results of the Rhino command _SystemInfo.

Also a screenshot of what you’re getting would be useful to understand what you’re seeing.

If you need me to investigate the file closer but don’t want to share it here, please upload it using rhino3d.com/upload?to=nathan@mcneel.com - when the upload is complete I’ll be automatically notified.