Please install the ubuntu-desktop meta package and try the upgrade again.
64 2016-01-08 12:22:31,840 DEBUG none of the '['ubuntu-desktop', 'kubuntu-desktop', 'xubuntu-core', 'xubuntu-desktop', 'ubuntustudio-desktop', 'mythbuntu-desktop' , 'kubuntu-netbook', 'lubuntu-core', 'lubuntu-desktop', 'ubuntu-gnome-desktop']' meta-pkgs installed
65 2016-01-08 12:22:31,841 DEBUG guessing 'ubuntu-desktop' as missing meta-pkg
66 2016-01-08 12:22:32,334 ERROR failed to mark 'ubuntu-desktop' for install (E:Probleme können nicht korrigiert werden, Sie haben zurückgehaltene defekte Pakete. )
67 2016-01-08 12:22:45,898 DEBUG blacklist expr 'unity$' matches 'unity'
68 2016-01-08 12:22:45,898 DEBUG The package 'unity' is marked for removal but it's in the removal blacklist
Please install the ubuntu-desktop meta package and try the upgrade again.
64 2016-01-08 12:22:31,840 DEBUG none of the '['ubuntu-desktop', 'kubuntu-desktop', 'xubuntu-core', 'xubuntu-desktop', 'ubuntustudio- desktop' , 'mythbuntu-desktop' , 'kubuntu-netbook', 'lubuntu-core', 'lubuntu-desktop', 'ubuntu- gnome-desktop' ]' meta-pkgs installed
65 2016-01-08 12:22:31,841 DEBUG guessing 'ubuntu-desktop' as missing meta-pkg
66 2016-01-08 12:22:32,334 ERROR failed to mark 'ubuntu-desktop' for install (E:Probleme können nicht korrigiert werden, Sie haben zurückgehaltene defekte Pakete. )
67 2016-01-08 12:22:45,898 DEBUG blacklist expr 'unity$' matches 'unity'
68 2016-01-08 12:22:45,898 DEBUG The package 'unity' is marked for removal but it's in the removal blacklist