cant upgrade from 12.04 to 14 or higher

[Aakash Deshpande]

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.

Restoring original system state

currently in 12.04, want to upgrade to 16

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.22
ProcVersionSignature: Ubuntu 3.13.0-117.164~precise1-generic 3.13.11-ckt39
Uname: Linux 3.13.0-117-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.0.1-0ubuntu17.15
Architecture: amd64
Date: Tue Sep 19 20:53:17 2017
InstallationMedia: Ubuntu 12.04.5 LTS "Precise Pangolin" - Release amd64 (20140807.1)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
Symptom: ubuntu-release-upgrader-core
UpgradeStatus: Upgraded to precise on 2017-09-20 (0 days ago)

[Launchpad Janitor (janitor)]

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