apt: Advanced front-end for dpkg Details: USN-3156-1 fixed vulnerabilities in APT. It also caused a bug in unattended-upgrades on that may require manual intervention to repair. Users on Ubuntu 16.10 should run the following commands at a terminal: sudo dpkg --configure --pending sudo apt-get -f install This update fixes the problem. We apologize for the inconvenience. Original advisory USN-3156-1 introduced a regression in unattended-upgrades that may require manual intervention to repair.