update-manager could not calculate the upgrade

[Rocky Gratiano]

I am trying to upgrade from 16.04.5 to 18.04.1 and I get the following error:

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done

Calculating the changes

Calculating the changes

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.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.25
ProcVersionSignature: Ubuntu 4.15.0-31.33~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-31-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Wed Aug 15 08:57:54 2018
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-03-04 (1990 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to xenial on 2018-08-15 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Antonello (antonelloventurino)]

I removed some broken package, founded from:

cat /var/log/dist-upgrade/apt.log | grep Broken

this fix the issue

[Rocky Gratiano (rockygratiano)]

Cool. Thank you, it worked!