Comment 19 for bug 278285

Good news! I was able to upgrade on my first machine.

I didn't really know what to do about removing the driver -- in my searching I got the idea to try "sudo apt-get remove nvidia-glx", and that removed some stuff and after a reboot didn't seem to affect my graphics situation. I had expected I might break something, but everything was working normally. (Is nvidia-glx the proprietary driver? I'm not even sure I'm using that -- I got this machine from System 76 and have never tinkered with the graphics driver at all.)

Also before trying the upgrade again, I installed a whole bunch of updates, so I don't know if there may have been a fix in there, but anyway, now when I ran the upgrade, it worked just fine -- no problems at all!

Thanks, Everyone, for your help with this. I'll report back with results on my other machine.