Unable to upgrade From 14.04LT Ubuntu to 15.04

[M. Rideout]

During the process of setting up new software channels a popup comes up that says, "Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

 This can be caused by:
 * Upgrading to a pre-release version of Ubuntu
 * Running the current pre-release version of Ubuntu
 * Unofficial software packages not provided by Ubuntu

If none of this applies, then please report this bug using the command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal.'

How do I resolve this problem?

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: ubuntu-release-upgrader-core 1:14.10.10
ProcVersionSignature: Ubuntu 3.16.0-37.51-generic 3.16.7-ckt9
Uname: Linux 3.16.0-37-generic x86_64
ApportVersion: 2.14.7-0ubuntu8.4
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Sun May 10 11:35:25 2015
InstallationDate: Installed on 2014-12-31 (129 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 2015-05-10 (0 days ago)
VarLogDistupgradeTermlog:

[Seth Arnold (seth-arnold)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

[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.

[M. Rideout (ridem92)]

How do I fix it?

On 2015-05-13 11:22 AM, Brian Murray wrote:
> *** This bug is a duplicate of bug 1069133 ***
> https://bugs.launchpad.net/bugs/1069133
>
> 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.
>
> ** Changed in: ubuntu-release-upgrader (Ubuntu)
> Status: New => Invalid
>
> ** Tags added: ppa xorg-edgers-ppa
>
> ** This bug has been marked a duplicate of bug 1069133
> Get upgrade error 12.04 - 12.10 "Could not determine upgrade" - xorg from ppa
>