Ubuntu desktop does not update packages, but internet connectivity from Browser is working fine

You have asked that I sent the following output to help with troubleshooting my issue. Basically my Ubuntu desktop 16.04 LTS is failing to get package updates, apparently with internet connectivity or proxy issues. However, the Firefox broser is able to access teh internet without any issues.

 I followed the 'Ask a question' link from your PackageManagerTroubleshootingProcedure web page at :https://help.ubuntu.com/community/PackageManagerTroubleshootingProcedure

Thanks
Ram

ram@ram-HP-Z820-Workstation:~$ ubuntu-support-status
Support status summary of 'ram-HP-Z820-Workstation':

You have 1717 packages (100.0%) that can not/no-longer be downloaded
You have 0 packages (0.0%) that are unsupported

Run with --show-unsupported, --show-supported or --show-all to see more details
ram@ram-HP-Z820-Workstation:~$ cat /etc/dpkg/dpkg.cfg.d/multiarch
cat: /etc/dpkg/dpkg.cfg.d/multiarch: No such file or directory
ram@ram-HP-Z820-Workstation:~$ dpkg --print-foreign-architectures
i386
ram@ram-HP-Z820-Workstation:~$ sudo grep -R proxy /etc/apt/*
ram@ram-HP-Z820-Workstation:~$ grep proxy /etc/environment
ram@ram-HP-Z820-Workstation:~$ echo $http_proxy

ram@ram-HP-Z820-Workstation:~$ echo $ftp_proxy

ram@ram-HP-Z820-Workstation:~$ grep proxy /etc/bash.bashrc
ram@ram-HP-Z820-Workstation:~$ grep proxy ~/.bashrc
ram@ram-HP-Z820-Workstation:~$ cat /etc/apt/apt.conf
cat: /etc/apt/apt.conf: No such file or directory
ram@ram-HP-Z820-Workstation:~$ sudo fuser -vvv /var/lib/dpkg/lock
ram@ram-HP-Z820-Workstation:~$ sudo fuser -vvv /var/cache/apt/archives/lock
ram@ram-HP-Z820-Workstation:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04 LTS"
ram@ram-HP-Z820-Workstation:~$ uname -a
Linux ram-HP-Z820-Workstation 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
ram@ram-HP-Z820-Workstation:~$ sudo rm /var/lib/apt/lists/lock
ram@ram-HP-Z820-Workstation:~$ sudo rm /var/cache/apt/archives/lock
ram@ram-HP-Z820-Workstation:~$ sudo rm /var/lib/dpkg/lock
ram@ram-HP-Z820-Workstation:~$ sudo cp -arf /var/lib/dpkg /var/lib/dpkg.backup
ram@ram-HP-Z820-Workstation:~$ sudo mv /var/lib/dpkg/status /var/lib/dpkg/status-bad
ram@ram-HP-Z820-Workstation:~$ sudo cp /var/lib/dpkg/status-old /var/lib/dpkg/status || sudo cp /var/backups/apt.extended_states.0 /var/lib/dpkg/status
ram@ram-HP-Z820-Workstation:~$ sudo mv /var/lib/dpkg/available /var/lib/dpkg/available-bad
ram@ram-HP-Z820-Workstation:~$ sudo cp /var/lib/dpkg/available-old /var/lib/dpkg/available
cp: cannot stat '/var/lib/dpkg/available-old': No such file or directory
ram@ram-HP-Z820-Workstation:~$ sudo rm -rf /var/lib/dpkg/updates/*
ram@ram-HP-Z820-Workstation:~$ sudo rm -rf /var/lib/apt/lists
ram@ram-HP-Z820-Workstation:~$ sudo rm /var/cache/apt/*.bin
ram@ram-HP-Z820-Workstation:~$ sudo mkdir /var/lib/apt/lists
ram@ram-HP-Z820-Workstation:~$ sudo mkdir /var/lib/apt/lists/partial
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get clean
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get autoclean
Reading package lists... Done
Building dependency tree
Reading state information... Done
ram@ram-HP-Z820-Workstation:~$ sudo dpkg --configure -a
ram@ram-HP-Z820-Workstation:~$ sudo dpkg --clear-avail
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get --fix-missing install
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get --purge autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get --fix-missing update -o APT::Cache-Limit=100000000
Get:1 http://archive.ubuntu.com/ubuntu xenial InRelease [8127 B]
Err:1 http://archive.ubuntu.com/ubuntu xenial InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [8127 B]
Err:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:3 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [8127 B]
Err:3 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:4 http://archive.ubuntu.com/ubuntu xenial-security InRelease [8127 B]
Err:4 http://archive.ubuntu.com/ubuntu xenial-security InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:5 http://archive.ubuntu.com/ubuntu xenial-proposed InRelease [8127 B]
Err:5 http://archive.ubuntu.com/ubuntu xenial-proposed InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Fetched 40.6 kB in 0s (45.1 kB/s)
Reading package lists... Done
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-security/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-proposed/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Some index files failed to download. They have been ignored, or old ones used instead.
ram@ram-HP-Z820-Workstation:~$ LANG=C;sudo apt-get update -o APT::Cache-Limit=100000000 && sudo apt-get dist-upgrade
Get:1 http://archive.ubuntu.com/ubuntu xenial InRelease [8127 B]
Err:1 http://archive.ubuntu.com/ubuntu xenial InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [8127 B]
Err:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:3 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [8127 B]
Err:3 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:4 http://archive.ubuntu.com/ubuntu xenial-security InRelease [8127 B]
Err:4 http://archive.ubuntu.com/ubuntu xenial-security InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:5 http://archive.ubuntu.com/ubuntu xenial-proposed InRelease [8127 B]
Err:5 http://archive.ubuntu.com/ubuntu xenial-proposed InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Fetched 40.6 kB in 1s (33.2 kB/s)
Reading package lists... Done
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-security/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-proposed/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Some index files failed to download. They have been ignored, or old ones used instead.
ram@ram-HP-Z820-Workstation:~$ find /etc/apt -name '*.list' -exec bash -c 'echo -e "\n$1\n"; cat -n "$1"' _ '{}' \;

/etc/apt/sources.list

     1 # deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
     2
     3 # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
     4 # newer versions of the distribution.
     5 deb http://archive.ubuntu.com/ubuntu/ xenial main restricted
     6 # deb-src http://archive.ubuntu.com/ubuntu/ xenial main restricted
     7
     8 ## Major bug fix updates produced after the final release of the
     9 ## distribution.
    10 deb http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted
    11 # deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted
    12
    13 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    14 ## team, and may not be under a free licence. Please satisfy yourself as to
    15 ## your rights to use the software. Also, please note that software in
    16 ## universe WILL NOT receive any review or updates from the Ubuntu security
    17 ## team.
    18 deb http://archive.ubuntu.com/ubuntu/ xenial universe
    19 # deb-src http://archive.ubuntu.com/ubuntu/ xenial universe
    20 deb http://archive.ubuntu.com/ubuntu/ xenial-updates universe
    21 # deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates universe
    22
    23 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    24 ## team, and may not be under a free licence. Please satisfy yourself as to
    25 ## your rights to use the software. Also, please note that software in
    26 ## multiverse WILL NOT receive any review or updates from the Ubuntu
    27 ## security team.
    28 deb http://archive.ubuntu.com/ubuntu/ xenial multiverse
    29 # deb-src http://archive.ubuntu.com/ubuntu/ xenial multiverse
    30 deb http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse
    31 # deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse
    32
    33 ## N.B. software from this repository may not have been tested as
    34 ## extensively as that contained in the main release, although it includes
    35 ## newer versions of some applications which may provide useful features.
    36 ## Also, please note that software in backports WILL NOT receive any review
    37 ## or updates from the Ubuntu security team.
    38 deb http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
    39 # deb-src http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
    40
    41 ## Uncomment the following two lines to add software from Canonical's
    42 ## 'partner' repository.
    43 ## This software is not part of Ubuntu, but is offered by Canonical and the
    44 ## respective vendors as a service to Ubuntu users.
    45 # deb http://archive.canonical.com/ubuntu xenial partner
    46 # deb-src http://archive.canonical.com/ubuntu xenial partner
    47
    48 deb http://archive.ubuntu.com/ubuntu/ xenial-security main restricted
    49 # deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
    50 deb http://archive.ubuntu.com/ubuntu/ xenial-security universe
    51 # deb-src http://security.ubuntu.com/ubuntu xenial-security universe
    52 deb http://archive.ubuntu.com/ubuntu/ xenial-security multiverse
    53 deb http://archive.ubuntu.com/ubuntu/ xenial-proposed main restricted multiverse universe
    54 # deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
ram@ram-HP-Z820-Workstation:~$ sudo dpkg --audit
ram@ram-HP-Z820-Workstation:~$ sudo dpkg --audit