Crashing on copy and save -- Rhino4

I’d been working for a few hours in Rhino4–not a big file, no real complicated objects–and on a simple command (changing layer display color) it suddenly crashed. Now, I can work inside the file–old or new–but if I try to Ctrl+C or save, save as, or export, it immediately crashes. I have tried restarting my computer, uninstalling and reinstalling rhino, installing updates, and restarting again with no change. Any suggestions??

There no way to know from just a description.
Assuming you are NOT running Rhino on an unsupported embedded Intel HD graphics chip, here’s what to do to narrow it down.

Start Rhino in Safe mode (there is a shortcut in the Rhinoceros Program group), and in Tools - Options - Appearance - OpenGL, REMOVE the check for the top option for using Accelerated hardware. Close Rhino and start normally. If Rhino starts without crashing, the problem was the display driver. Then go look for an updated driver. If Rhino still crashes after downloading and installing an updated display driver, then the problem most likely is a plug-in.

In that case, restart in Safe mode, ADD the check back for accelerated hardware graphics. Then go into Tools - Options - Plug-ins, and add checks in the Load Protect box for all of the plug-ins you have installed.

Then restart Rhino normally (not in Safe mode), and when asked to load the plug-ins, answer No to all. If Rhino comes up without crashing, the problem is one of the load protected plug-ins. Restart Rhino normally again, and this time, answer Yes to loading the first plug-in and No to the rest. If Rhino crashes when loading the first one, that plug-in is the problem. If it doesn’t crash, it’s not. Go back into the Plug-ins page and remove the load protect check for that plug-in. Restart Rhino again and repeat that process until you find the crashing plug-in.

Good luck