Comment 2 for bug 989072

Unpacking libtag1c2a:i386 (from .../libtag1c2a_1.7-1ubuntu5_i386.deb) ...
(Noting disappearance of libtag1c2a, which has been completely replaced.)

This is bug #902603. As documented in the release notes for 12.04, users of 11.10 64-bit need to upgrade apt and dpkg to the versions on oneiric-updates before upgrading to 12.04.

To recover from this, you will need to manually run 'sudo dpkg -i /var/cache/apt/archives/libtag1c2a_1.7-1ubuntu5_amd64.deb' from a terminal, followed by 'sudo apt-get -f install'.