Comment 3 for bug 1609176

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Since it seems likely to me that this is a local configuration problem, rather than a bug in Ubuntu, I'm marking this bug as Incomplete.

modified.conffile..etc.libvirt.qemu.networks.default.xml: [modified]
mtime.conffile..etc.libvirt.qemu.networks.default.xml: 2016-08-02T16:10:14.464558

Specifically, you have modified libvirt's configuration locally on your system, so it seems likely to me that this is a cause of your upgrade problem.

If indeed this is a local configuration problem, you can find pointers to get help for this sort of problem here: http://www.ubuntu.com/support/community

Or if you believe that this is really a bug, then you may find it helpful to read "How to report bugs effectively" http://www.chiark.greenend.org.uk/~sgtatham/bugs.html. We'd be grateful if you would then provide a more complete description of the problem, explain why you believe this is a bug in Ubuntu rather than a problem specific to your system, and then change the bug status back to New.