You seem to have both the ubuntu-desktop and kubuntu-desktop meta packages installed. This ends up causing an issue in the following way:
2015-09-27 04:04:50,957 DEBUG Installing 'baloo-kf5' (kubuntu-desktop PostUpgradeInstall rule) 2015-09-27 04:04:50,958 DEBUG Removing 'xscreensaver' (ubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,958 DEBUG Removing 'gnome-cups-manager' (ubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,958 DEBUG Removing 'powermanagement-interface' (ubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,958 DEBUG Removing 'deskbar-applet' (ubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,959 DEBUG Removing 'nautilus-cd-burner' (ubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,959 DEBUG Removing 'powermanagement-interface' (kubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,959 DEBUG Removing 'guidance-power-manager' (kubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,959 DEBUG Removing 'kde-guidance-powermanager' (kubuntu-desktop PostUpgradeRemove rule) 2015-09-27 04:04:50,960 DEBUG plugins for condition 'PostDistUpgradeCache' are '[]' 2015-09-27 04:04:50,960 DEBUG plugins for condition 'wilyPostDistUpgradeCache' are '[]' 2015-09-27 04:04:50,960 DEBUG plugins for condition 'from_vividPostDistUpgradeCache' are '[]' 2015-09-27 04:04:50,961 DEBUG Marking 'ubuntu-desktop' for upgrade 2015-09-27 04:04:52,575 DEBUG Marking 'kubuntu-desktop' for upgrade 2015-09-27 04:04:55,752 WARNING Can't mark 'kubuntu-desktop' for upgrade (E:Errore, pkgProblemResolver::Resolve ha generato delle interruzioni. Questo potrebbe essere causato da pacchetti bloccati.) 2015-09-27 04:04:56,060 DEBUG blacklist expr 'ubuntu-release-upgrader' matches 'ubuntu-release-upgrader-qt' 2015-09-27 04:04:56,060 DEBUG The package 'ubuntu-release-upgrader-qt' is marked for removal but it's in the removal blacklist Looking at Aptlog.txt - I actually think this is just and issue with the kubuntu upgrade. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1500130 Title: trying to upgrade to beta to test To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1500130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs