Comment 4 for bug 1573662

After using the GUI to initiate dist-upgrade from 15.10 to 16.04 and encountering the error described above related to the gconf2 package the automatic reboot resulted in an undefined state that resembled a reboot loop. I eventually tired of waiting, switched to TTY1 and pressed ctrl-alt-delete. This seems to have succeeded switching to runlevel 6 and it became clear the machine had not yet completely shutdown following the upgrade. The reboot succeeded but the window manager failed to run. I switched to a TTY with a login prompt and was dropped into a shell. I ran the command prescribed by Sebastian and was prompted to instead run dpkg to complete a package operation that had been interrupted. I did so and was prompted several times to accept the maintainer's version of files that had changed on my computer and did so without exception. After dpkg completed successfully I again ran apt-get dist-upgrade and autoremove successfully and rebooted. This time the window manager presented normally and everything seems fine so far.