16.04 Upgrade fails with error W:Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/xenial/universe/source/Sources 404

[sumit ajin]

Upgrade to 16.04 from 14.04 fails with the following error:

W:Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/xenial/universe/source/Sources 404 Not Found [IP: 91.189.88.152 80]
, W:Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/xenial/universe/binary-amd64/Packages 404 Not Found [IP: 91.189.88.152 80]
, W:Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/xenial/universe/binary-i386/Packages 404 Not Found [IP: 91.189.88.152 80]
, E:Some index files failed to download. They have been ignored, or old ones used instead.'.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.8
ProcVersionSignature: Ubuntu 3.19.0-61.69~14.04.1-generic 3.19.8-ckt21
Uname: Linux 3.19.0-61-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.21
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Thu Aug 25 15:57:53 2016
InstallationDate: Installed on 2015-09-03 (357 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_IN:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IN
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2016-08-24 (1 days ago)
VarLogDistupgradeAptlog:
 Log time: 2016-08-24 11:40:16.704266
 Log time: 2016-08-24 11:43:15.188964
 Log time: 2016-08-24 12:18:59.469510
VarLogDistupgradeTermlog:

[Launchpad Janitor (janitor)]

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