Comment 24 for bug 249340

This is what worked for me thanks to folks (behda) on the Ubuntu forums. I did not lose any data and it worked just fine.

1 start PC and let it load to X login screen (after getting X setup popup and choosing continue)
2 do a ctrl+alt+F1 and get to terminal and login.
3 sudo rm /usr/bin/localedef
4 sudo dpkg --configure -a
5 let upgrade finish and when back to the prompt "reboot"