Found inspiration for a work-around on this page: http://askubuntu.com/questions/475972/error-couldnt-find-rgb-glx-visual- or-fbconfig-ubuntu-12-04/476916#476916
This is NOT TRIVIAL. I started by trying to follow that page's recommendations, replacing "xserver-xorg" with "xserver-common", and BORKED X entirely, to the point where I couldn't use the keyboard or see things on the screen. Fortunately I was able to ssh into the system. I did a lot of mucking about, but what will probably work is: sudo apt-get remove --purge xserver-common sudo apt-get install xorg I do NOT recommend this if you're shy around computers, or if you don't have a reliable way to ssh into your sick box. I'm sure there's a very- much-better way of solving the problem, but I'm not good enough to know it. ** Also affects: xorg-server (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1639371 Title: OpenGL Graphics broken on November 4th upgrades To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/freecad/+bug/1639371/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs