Unable to upgrade and update Ubuntu 15.04

[Matthieu Charton]

It has been months since I received an update for any program, and attempts to upgrade my ubuntu 15.04 to either 15.10 or 16.04 result in an unsolvable error.

"
Impossible d'évaluer la mise à niveau

Un problème insoluble est survenu lors de la préparation de la mise à
niveau.
"

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: ubuntu-release-upgrader-core 1:15.04.14.3
ProcVersionSignature: Ubuntu 3.19.0-58.64-generic 3.19.8-ckt16
Uname: Linux 3.19.0-58-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.17.2-0ubuntu1.8
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Mon May 2 13:19:49 2016
InstallationDate: Installed on 2015-03-07 (422 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to vivid on 2016-05-02 (0 days ago)

[Ubuntu Foundations Team Bug Bot (crichton)]

Reviewing the files from your upgrade attempt you seem to have enabled the xorg-edgers-ppa. This will prevent the upgrade as that PPA contains different versions of packages essential to Ubuntu. The page, https://launchpad.net/~xorg-edgers/+archive/ppa, contains details on to how to revert to the official Xorg packages. Thanks.

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[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1069133, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.
[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]