Unable to Upgrade from v14.04 to 16.04

[John Dorman]

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

#### Problem after this point ####

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

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.9
ProcVersionSignature: Ubuntu 4.4.0-57.78~14.04.1-generic 4.4.35
Uname: Linux 4.4.0-57-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.14.1-0ubuntu3.23
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Wed Jan 4 18:16:26 2017
InstallationDate: Installed on 2016-03-25 (285 days ago)
InstallationMedia: Ubuntu 14.04.4 LTS "Trusty Tahr" - Release amd64 (20160217.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2017-01-05 (0 days ago)