Failed to install Ubuntu Studio from 14.04 directly to 16.04

[TBerk]

Update failed citing 'Third Party entries in Sources List..' (paraphrased).

This is an Asus laptop w/ Intel chipset, 4G RAM, dual core Celeron CPU.

(I'm understanding the actual bug report is contained in an included report...)

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.8
ProcVersionSignature: Ubuntu 3.16.0-72.93~14.04.1-lowlatency 3.16.7-ckt27
Uname: Linux 3.16.0-72-lowlatency x86_64
ApportVersion: 2.14.1-0ubuntu3.21
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: XFCE
Date: Sat May 28 18:20:17 2016
InstallationDate: Installed on 2015-12-10 (170 days ago)
InstallationMedia: Ubuntu-Studio 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2016-05-29 (0 days ago)

[TBerk (bayareaberk-yahoo)]

Forgot to specify I was attempting to Upgrade, from a Terminal window, from Ubuntu Studio 14.04 directly to Ubuntu Studio 16.04.

TBerk