I suppose this is an upgrade-manager problem then. I'm attaching /var/log/dist-upgrade/*.
Note that after the upgrade, there was neither a "light" nor a "human" theme available in System -> Preferences -> Appearance. I fixed the problem by manually installing the human theme.
It seems to me that one of the ubuntu-* packages really ought to depend on a proper theme, so I'm adding ubuntu-desktop as well.
I suppose this is an upgrade-manager problem then. I'm attaching /var/log/ dist-upgrade/ *.
Note that after the upgrade, there was neither a "light" nor a "human" theme available in System -> Preferences -> Appearance. I fixed the problem by manually installing the human theme.
It seems to me that one of the ubuntu-* packages really ought to depend on a proper theme, so I'm adding ubuntu-desktop as well.