I had almost exactly the same as Maketsi (comment 22) just now in my upgrade from 16.04 to 16.10, with the one difference that my gconf2 is a newer version than theirs and mine is set to manually installed (not sure why). Same experience as hackel (comment 24) too, in that I rebooted (although upgrader had crashed and didn't tell me to reboot, so I wasn't even sure if it was stable enough to reboot) and everything is apparently up to date and stable.
# sudo apt upgrade gconf2 [sudo] password for michael: Reading package lists... Done Building dependency tree Reading state information... Done gconf2 is already the newest version (3.2.6-3ubuntu7). gconf2 set to manually installed. Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gconf in Ubuntu. https://bugs.launchpad.net/bugs/1551623 Title: package gconf2 3.2.6-3ubuntu6 failed to install/upgrade: dependency problems - leaving triggers unprocessed Status in gconf package in Ubuntu: Triaged Bug description: When upgrading from 15.10 to 16.04Beta (2016-03-01), this error occured, alongside many others related to systemd and gnome. Notice that despite all warnings and errors, finally, the system remained functional. ProblemType: Package DistroRelease: Ubuntu 16.04 Package: gconf2 3.2.6-3ubuntu6 ProcVersionSignature: Ubuntu 4.4.0-8.23-generic 4.4.2 Uname: Linux 4.4.0-8-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 Date: Tue Mar 1 09:21:15 2016 ErrorMessage: dependency problems - leaving triggers unprocessed InstallationDate: Installed on 2015-10-04 (148 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20151002) RelatedPackageVersions: dpkg 1.18.4ubuntu1 apt 1.2.3 SourcePackage: gconf Title: package gconf2 3.2.6-3ubuntu6 failed to install/upgrade: dependency problems - leaving triggers unprocessed UpgradeStatus: Upgraded to xenial on 2016-03-01 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gconf/+bug/1551623/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp