Marker says "The update information is outdated."

Please provide the full output of the commands

uname -a
lsb_release -crid
sudo apt-get update
cat -n /etc/apt/sources.list
cat -n /etc/apt/sources.list.d/precise-partner.list

when executed in a terminal window.

Sorry, but I can not provide all information at the moment but I think the following is quite enough

Linux tpollak-XPS 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:15
UTC 2016 i686 i686 i686 GNU/Linux

Distributor ID: Ubuntu
Description: Ubuntu 16.04 LTS
Release: 16.04
Codename: xenial

Hit:1 http://se.archive.ubuntu.com/ubuntu xenial InRelease
Ign:2 http://dl.google.com/linux/talkplugin/deb stable InRelease
Hit:3 http://se.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:4 http://archive.canonical.com/ubuntu xenial InRelease
Get:6 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB]
Get:5 http://dl.google.com/linux/talkplugin/deb stable Release [1,347 B]
Get:7 http://dl.google.com/linux/talkplugin/deb stable Release.gpg [198 B]
Hit:8 http://se.archive.ubuntu.com/ubuntu xenial-backports InRelease
Ign:9 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal InRelease
Hit:10 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal Release
Fetched 96.0 kB in 0s (123 kB/s)
Reading package lists...
Hit:1 http://se.archive.ubuntu.com/ubuntu xenial InRelease
Hit:2 http://se.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:3 http://archive.canonical.com/ubuntu xenial InRelease
Get:4 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB]
Hit:5 http://se.archive.ubuntu.com/ubuntu xenial-backports InRelease
Ign:6 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal InRelease
Hit:7 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal Release
Ign:9 http://dl.google.com/linux/talkplugin/deb stable InRelease
Get:10 http://dl.google.com/linux/talkplugin/deb stable Release [1,347 B]
Get:11 http://dl.google.com/linux/talkplugin/deb stable Release.gpg [198 B]
Fetched 96.0 kB in 1s (92.7 kB/s)
Reading package lists...

...

/etc/apt/sources.list and ...d/precise-partner.list do not exist

Tried once more after having solved problem with missing menu in Terminal gave a different result.

~$ uname -a
Linux tpollak-XPS 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:15 UTC 2016 i686 i686 i686 GNU/Linux
~$ lsb_release-crid
lsb_release-crid: command not found
~$ lsb_release -crid
Distributor ID: Ubuntu
Description: Ubuntu 16.04 LTS
Release: 16.04
Codename: xenial
~$ sudo apt-get update
[sudo] password for tpollak:
Ign:1 http://dl.google.com/linux/talkplugin/deb stable InRelease
Hit:2 http://se.archive.ubuntu.com/ubuntu xenial InRelease
Hit:4 http://se.archive.ubuntu.com/ubuntu xenial-updates InRelease
Get:5 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB]
Get:3 http://dl.google.com/linux/talkplugin/deb stable Release [1,347 B]
Hit:6 http://se.archive.ubuntu.com/ubuntu xenial-backports InRelease
Get:7 http://dl.google.com/linux/talkplugin/deb stable Release.gpg [198 B]
Hit:8 http://archive.canonical.com/ubuntu xenial InRelease
Ign:9 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal InRelease
Hit:10 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal Release
Fetched 96.0 kB in 0s (124 kB/s)
Reading package lists... Done
W: Target Packages (partner/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Packages (partner/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Translations (partner/i18n/Translation-en_GB) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Translations (partner/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Translations (partner/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target DEP-11 (partner/dep11/Components-i386.yml) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target DEP-11-icons (partner/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: http://dl.google.com/linux/talkplugin/deb/dists/stable/Release.gpg: Signature by key 4CCA1EAF950CEE4AB83976DCA040830F7FAC5991 uses weak digest algorithm (SHA1)
W: https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu/dists/quantal/Release.gpg: Signature by key 33E0E91BDD8E7F4B53837F09E131728675254D99 uses weak digest algorithm (SHA1)
E: Failed to fetch http://dl.google.com/linux/talkplugin/deb/dists/stable/Release No Hash entry in Release file /var/lib/apt/lists/partial/dl.google.com_linux_talkplugin_deb_dists_stable_Release which is considered strong enough for security purposes
E: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Packages (partner/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Packages (partner/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Translations (partner/i18n/Translation-en_GB) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Translations (partner/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target Translations (partner/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target DEP-11 (partner/dep11/Components-i386.yml) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
W: Target DEP-11-icons (partner/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:50 and /etc/apt/sources.list.d/precise-partner.list:1
~$ cat -n /etc/apt/sources.list
     1 # deb cdrom:[Ubuntu 12.04.1 LTS _Precise Pangolin_ - Release i386 (20120817.3)]/ precise 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://se.archive.ubuntu.com/ubuntu/ xenial main restricted
     6 deb-src http://se.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://se.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
    11 deb-src http://se.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
    12
    13 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    14 ## team. Also, please note that software in universe WILL NOT receive any
    15 ## review or updates from the Ubuntu security team.
    16 deb http://se.archive.ubuntu.com/ubuntu/ xenial universe
    17 deb-src http://se.archive.ubuntu.com/ubuntu/ xenial universe
    18 deb http://se.archive.ubuntu.com/ubuntu/ xenial-updates universe
    19 deb-src http://se.archive.ubuntu.com/ubuntu/ xenial-updates universe
    20
    21 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    22 ## team, and may not be under a free licence. Please satisfy yourself as to
    23 ## your rights to use the software. Also, please note that software in
    24 ## multiverse WILL NOT receive any review or updates from the Ubuntu
    25 ## security team.
    26 deb http://se.archive.ubuntu.com/ubuntu/ xenial multiverse
    27 deb-src http://se.archive.ubuntu.com/ubuntu/ xenial multiverse
    28 deb http://se.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
    29 deb-src http://se.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
    30
    31 ## N.B. software from this repository may not have been tested as
    32 ## extensively as that contained in the main release, although it includes
    33 ## newer versions of some applications which may provide useful features.
    34 ## Also, please note that software in backports WILL NOT receive any review
    35 ## or updates from the Ubuntu security team.
    36 deb http://se.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
    37 deb-src http://se.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
    38
    39 deb http://security.ubuntu.com/ubuntu xenial-security main restricted
    40 deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
    41 deb http://security.ubuntu.com/ubuntu xenial-security universe
    42 deb-src http://security.ubuntu.com/ubuntu xenial-security universe
    43 deb http://security.ubuntu.com/ubuntu xenial-security multiverse
    44 deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
    45
    46 ## Uncomment the following two lines to add software from Canonical's
    47 ## 'partner' repository.
    48 ## This software is not part of Ubuntu, but is offered by Canonical and the
    49 ## respective vendors as a service to Ubuntu users.
    50 deb http://archive.canonical.com/ubuntu xenial partner
    51 # deb-src http://archive.canonical.com/ubuntu precise partner
    52
    53
    54 ## Preview of Spotify for Linux according to Spotify's web server /Tommy Pollak on 2013-01-24
    55 # deb http://repository.spotify.com stable non-free # disabled on upgrade to quantal
~$ cat -n /etc/apt/sources.list.d/precise-partner.list
     1 deb http://archive.canonical.com/ubuntu xenial partner #Added by software-center
~$

Did you by any chance upgrade directly from Precise to Xenial in one jump by editing the sources.list file?

No, I upgraded from 15.10 by the book.

Seems that the icon is gone now that the sources.list exists again.

Do you mean upgrading to Trusty then to Utopic?

No, from 15.10 Wiley to 16.04 Xenial.

The warning icon is back again ...

try the command

sudo rm /etc/apt/sources.list.d/precise-partner.list

This should eliminate the 'duplicate sources' error.

For the case with the google repository:
The newest Ubuntu releases expect stronger cryptographic security measures than those that google provides.
You should disable the google talkplugin repository until google provides adequate security.

What is the output of the command

grep google /etc/apt/sources.list /etc/apt/source.list.d/*.list

~$ sudo rm -i /etc/apt/sources.list.d/precise-partner.list
[sudo] password for tpollak:
rm: remove regular file '/etc/apt/sources.list.d/precise-partner.list'? y

repository disabled

~$ grep google /etc/apt/sources.list /etc/apt/source.list.d/*.list
grep: /etc/apt/source.list.d/*.list: No such file or directory
~$

Sorry, a typo error in my command (missing character), try again with

grep google /etc/apt/sources.list /etc/apt/sources.list.d/*.list

No problem

~/.../Fotoalbum$ grep google /etc/apt/sources.list /etc/apt/sources.list.d/*list
/etc/apt/sources.list.d/google-earth.list:# deb http://dl.google.com/linux/earth/deb/ stable main # disabled on upgrade to wily
/etc/apt/sources.list.d/google-talkplugin.list:# deb http://dl.google.com/linux/talkplugin/deb/ stable main
~/.../Fotoalbum$

Ok. The Google repositories are currently disabled.

Running

sudo apt-get update

should now show no errors any more. Please try and report the results.

~$ sudo apt-get update
[sudo] password for tpollak:
Hit:1 http://se.archive.ubuntu.com/ubuntu xenial InRelease
Get:2 http://se.archive.ubuntu.com/ubuntu xenial-updates InRelease [94.5 kB]
Hit:3 http://archive.canonical.com/ubuntu xenial InRelease
Hit:4 http://security.ubuntu.com/ubuntu xenial-security InRelease
Hit:5 http://se.archive.ubuntu.com/ubuntu xenial-backports InRelease
Ign:6 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal InRelease
Hit:7 https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu quantal Release
Get:8 http://se.archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [113 kB]
Get:9 http://se.archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [53.1 kB]
Fetched 261 kB in 0s (397 kB/s)
Reading package lists... Done
W: https://private-ppa.launchpad.net/commercial-ppa-uploaders/master-pdf-editor/ubuntu/dists/quantal/Release.gpg: Signature by key 33E0E91BDD8E7F4B53837F09E131728675254D99 uses weak digest algorithm (SHA1)
~$