I get the same crash with the trace below, (Fresh quantal 20121012 amd64 install -> Re-install quantal desktop 20121012 i386 keeping the personal files and then use software center to install any application e.g. virt manager)
Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/defer/__init__.py", line 487, in _inline_callbacks result.traceback) File "/usr/share/software-center/softwarecenter/backend/installbackend_impl/aptd.py", line 957, in _medium_required yield transaction.cancel(defer=True) aptdaemon.errors.AptDaemonError: org.debian.apt: Could not cancel transaction Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/defer/__init__.py", line 487, in _inline_callbacks result.traceback) File "/usr/share/software-center/softwarecenter/backend/installbackend_impl/aptd.py", line 957, in _medium_required yield transaction.cancel(defer=True) aptdaemon.errors.AptDaemonError: org.debian.apt: Could not cancel transaction -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/751725 Title: software-center crashed with AptDaemonError in _medium_required(): org.debian.apt: Could not cancel transaction To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/aptdaemon/+bug/751725/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs