i was upgrading from ubuntu 17.1 to 18, one machine was upgraded, but another (this) machine is not upgrading

[Harcharan Singh]

i was upgrading from ubuntu 17.10 to 18, one machine was upgraded successfully, but another (this) machine is not upgrading it 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

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: ubuntu-release-upgrader-core 1:17.10.11
ProcVersionSignature: Ubuntu 4.13.0-39.44-generic 4.13.16
Uname: Linux 4.13.0-39-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.8
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Mon May 7 15:10:37 2018
InstallationDate: Installed on 2018-03-16 (52 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to artful on 2018-05-07 (0 days ago)
VarLogDistupgradeTermlog:

[dino99 (9d9)]

The error found:

The package 'update-manager' is marked for removal but it's in the removal blacklist

Dupe of Bug #1768620

[Jean-Baptiste Lallement (jibel)]

Thanks for your report.

Unlike what dino99 said, this is not a duplicate but caused by the xorg stack installed from the oibaf PPA. Please revert to official version of these package and try to upgrade again.

Don't hesitate to file any bug you may find.

[Jean-Baptiste Lallement (jibel)]

@dino, again this is not a duplicate update-manager is in the removal blacklist on purpose because it is a critical component of the upgrade system and must not be removed during a release upgrade. So please don't update this bug.