I experienced this exact problem, and can shine some light on what's happening.
The bug is: Ubiquity gives an unclear error message. Instead of something cryptic about the internals of the process, it should say "cloop image not found. Please run Ubiquity from the install CD or mount the cloop image on /var/lib/ubiquity/source" or preferable something even less cryptical. ---- I made a temporary install with debootstrap, then installed ubiquity to make the real install, the same staged approach as Original Poster here tried. This because the target computer lacks a CD drive. The problem is this: Ubiquity expects to be run from the install CD. After formatting partitions it expects to find /cdrom/casper/filesystem.squashfs or equivalent, to mount on /var/lib/ubiquity/source. The next step is to copy the contents of said directory to /target. If Ubiquity cannot find the CD cloop image in any of the expected locations, it happily continues with an empty /var/lib/ubiquity/source, copies all its non-existing contents to /target, then goes on to customize the copied filesystem. The first thing it does is set the language, by writing /etc/default/locale. Since /etc/default does not exist, the application breaks down at this point, with the error message noted in the bug report. So, workaround: Don't run ubiquity except from the CD. Or first mount the cloop image on /var/lib/ubiquity/sources. I did the latter, and successfully installed my system. Hopefully by noting this here, the next person to try this will be more lucky when searching for a solution. Adding a feature request that running ubiquity from outside the install CD should work. I have ideas for this. :-) /c -- Installer crashed https://bugs.launchpad.net/bugs/189193 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs