can't upgrade from 14.10 to 15.04

[SlyK]

I had Ubuntu 14.04 with core from 14.10. Then wanted ro upgrade to 15.04. Seems like I have to do this only by going to 14.10 version before 15.04. But after successfull upgrade to 14.10 it seems like I can't upgrade further.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: ubuntu-release-upgrader-core 1:14.10.10
ProcVersionSignature: Ubuntu 3.16.0-38.52-generic 3.16.7-ckt10
Uname: Linux 3.16.0-38-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.7-0ubuntu8.5
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Wed Jun 10 19:09:37 2015
InstallationDate: Installed on 2014-11-20 (201 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to utopic on 2015-06-10 (0 days ago)

[SlyK (slykirill)]

Wee found the solution for my current problem is xserver-*. I think Ubuntu must advice people to analyse apt.log or even display error messages from there and say what commands may help.

For me, the solve procedure was:

1. Open latest apt.log from /var/log/dist-upgrade
2. Find lines with problems, starting with "Broken..."
3. Remove that packages using "apt-get remove <names>"
4. Finally run "do-release-upgrade"

[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.]