Running Ubuntu 15.10 32-bit under Parallels Desktop 11.
I the updater today, which included a new kernel. After reboot the login screen comes up fine, but upon login, my desktop background and resolution updated, but no unity panel or other windows showed up. Investigation revealed that compiz was segfaulting repeatedly and the window manager could not come up at all.
I attempted a re-install from scratch and the first thing I did after install was run updates -- same problem happened right away (though I could not 100% confirm it was compiz crashing because I neglected to install ssh-server before running updates -- but it "looked" the same visually.