Ubuntu installer crashed after reinstallation

[Romanjn]

Removed an old install then got a new one. Lost internet connexion during the installation and kept going but it wasn't functionnal (froze on first boot). Reinstalling now with stable internet connexion with Lili USB live CD and it crashed...
Note that it crashed near the end of the installation (after or during grub configuration).

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubiquity 2.18.8.6
ProcVersionSignature: Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3
Uname: Linux 3.16.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CasperVersion: 1.340
Date: Mon May 11 19:35:24 2015
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash --
LiveMediaBuild: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Reviewing your log files attached to this bug report it seems that there is a problem with your installation media (CD/DVD). You can verify the integrity of the Ubuntu ISO files you downloaded by following the instructions at https://help.ubuntu.com/community/HowToMD5SUM. You might also retry your installation with new media. In the event that is is not in fact an error with your installation media please set the bug's status back to New. Thanks and good luck!

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Launchpad Janitor (janitor)]

[Expired for ubiquity (Ubuntu) because there has been no activity for 60 days.]