Comment 26 for bug 766412

apt-get update && apt-get updgrade will still fail as of today. It will not let you properly install language-selector-common. I have confirmed that you need to edit a file for post installation:

sudo vi /var/lib/dpkg/info/language-selector-common.postinst

Look for this line:

kill $(pgrep -U root '^ls-dbus-backend$') 2>/dev/null

append || true so that its look like:

kill $(pgrep -U root '^ls-dbus-backend$') 2>/dev/null || true

then run:

 sudo apt-get update && sudo apt-get upgrade

This method will fix the issue, a simple apt-get upgrade will not fix the problems as of yet.