update manager crashes on upgrade from 12.10

[Josh Milthorpe]

The update manager failed, saying it could not calculate the upgrade.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: ubuntu-release-upgrader-core 1:0.190.8
ProcVersionSignature: Ubuntu 3.7.0-7.15-generic 3.7.0
Uname: Linux 3.7.0-7-generic x86_64
ApportVersion: 2.6.1-0ubuntu13
Architecture: amd64
Date: Fri May 30 11:42:00 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2012-12-07 (539 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to quantal on 2014-05-30 (0 days ago)
VarLogDistupgradeTermlog:

[Brian Murray (brian-murray)]

Reviewing the files from your upgrade attempt you seem to have enabled a PPA that provides Xorg packages. 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 for the xorg-edgers PPA. Instructions for reverting to official Xorg packages should be similar for the PPA that you have enabled.