Using 2-22-2021 Rhino 7 on Windows 10 Pro.
I was trying to join 2 coplanar surfaces that had come from exploding the result of a squish. I hadn’t done anything with them after exploding but had worked on some others. I don’t recall which view mode I was using: probably default shaded.
What happened was during the join the all viewports disappeared and the main Rhino background turned black. I apologize for not submitting the crash report. I was impatient and thought a simple restart of Rhino would get me going again. Not so. When Rhino shutdown it left my Windows user background all black. Rebooting didn’t fix it. Rebooting and resetting the Windows background under settings restored it.
I can’t guess whether this info will be of much use without the crash report, but here it is. If it happens again I’ll send the report, but I intend to install yesterday’s RC this afternoon.