Error Ubuntu 16.04.3 with blank screen after login

Asked by surendra on 2017-08-04

root@ubuntu:/# uname -a
Linux ubuntu 3.8.0-29-generic #42~precise1-Ubuntu SMP Wed Aug 14 15:31:16 UTC 2013 i686 i686 i686 GNU/Linux

root@ubuntu:/# lsb_release -crid
Distributor ID: Ubuntu
Description: Ubuntu 16.04.3 LTS
Release: 16.04
Codename: xenial

root@ubuntu:/# sudo dpkg --configure -a

root@ubuntu:/# sudo apt-get install -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  linux-headers-4.4.0-83 linux-headers-4.4.0-83-generic
  linux-hwe-edge-tools-4.10.0-26 linux-image-4.4.0-83-generic
  linux-image-extra-4.4.0-83-generic linux-tools-4.10.0-26-generic
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

root@ubuntu:/# sudo dpkg --audit
root@ubuntu:/#

root@ubuntu:/# sudo apt-key list
/etc/apt/trusted.gpg
--------------------
pub 1024D/437D05B5 2004-09-12
uid Ubuntu Archive Automatic Signing Key <email address hidden>
sub 2048g/79164387 2004-09-12

pub 1024D/FBB75451 2004-12-30
uid Ubuntu CD Image Automatic Signing Key <email address hidden>

pub 4096R/C0B21F32 2012-05-11
uid Ubuntu Archive Automatic Signing Key (2012) <email address hidden>

pub 4096R/EFE21092 2012-05-11
uid Ubuntu CD Image Automatic Signing Key (2012) <email address hidden>

pub 1024D/7FAC5991 2007-03-08
uid Google, Inc. Linux Package Signing Key <email address hidden>
sub 2048g/C07CB649 2007-03-08

pub 4096R/2980AECF 2016-04-22
uid Oracle Corporation (VirtualBox archive signing key) <email address hidden>
sub 4096R/920E471F 2016-04-22

pub 4096R/D38B4796 2016-04-12
uid Google Inc. (Linux Packages Signing Authority) <email address hidden>
sub 4096R/640DB551 2016-04-12 [expires: 2019-04-12]

/etc/apt/trusted.gpg.d/flexiondotorg_ubuntu_hal-flash.gpg
---------------------------------------------------------
pub 1024R/93D8809A 2011-03-16
uid Launchpad PPA for Martin Wimpress

/etc/apt/trusted.gpg.d/mc3man-trusty-media.gpg
----------------------------------------------
pub 1024R/ED8E640A 2013-05-20
uid Launchpad PPA for Doug McMahon

/etc/apt/trusted.gpg.d/rvm-smplayer.gpg
---------------------------------------
pub 1024R/E4A4F4F4 2009-04-10
uid Launchpad PPA named smplayer for rvm

/etc/apt/trusted.gpg.d/strukturag_ubuntu_libde265.gpg
-----------------------------------------------------
pub 1024R/705C2B92 2013-11-07
uid Launchpad PPA for struktur AG

/etc/apt/trusted.gpg.d/ubuntu-mate-dev_ubuntu_welcome.gpg
---------------------------------------------------------
pub 4096R/162506E7 2014-06-24
uid Launchpad PPA for Ubuntu MATE Remix Developers

/etc/apt/trusted.gpg.d/ubuntu-mate-dev_ubuntu_xenial-mate.gpg
-------------------------------------------------------------
pub 4096R/162506E7 2014-06-24
uid Launchpad PPA for Ubuntu MATE Remix Developers

/etc/apt/trusted.gpg.d/webupd8team-java.gpg
-------------------------------------------
pub 1024R/EEA14886 2010-05-04
uid Launchpad VLC

/etc/apt/trusted.gpg.d/wine_ubuntu_wine-builds.gpg
--------------------------------------------------
pub 4096R/77C899CB 2015-11-21
uid Launchpad PPA for Wine

/etc/apt/trusted.gpg.d/yannubuntu-boot-repair.gpg
-------------------------------------------------
pub 1024R/60D8DA0B 2010-12-27
uid Launchpad PPA for YannUbuntu

/etc/apt/trusted.gpg.d/yannubuntu_ubuntu_boot-repair.gpg
--------------------------------------------------------
pub 1024R/60D8DA0B 2010-12-27
uid Launchpad PPA for YannUbuntu

root@ubuntu:/# ls -l /var/lib/apt/lists/
total 149012
-rw-r--r-- 1 root root 9513 Jul 11 21:33 archive.canonical.com_ubuntu_dists_xenial_partner_binary-i386_Packages
-rw-r--r-- 1 root root 4228 Jul 1 04:19 archive.canonical.com_ubuntu_dists_xenial_partner_i18n_Translation-en
-rw-r--r-- 1 root root 6611 Jul 11 21:33 archive.canonical.com_ubuntu_dists_xenial_partner_source_Sources
-rw-r--r-- 1 root root 11491 Jul 11 21:33 archive.canonical.com_ubuntu_dists_xenial_Release
-rw-r--r-- 1 root root 18534 Jul 6 11:24 archive.ubuntu.com_ubuntu_dists_xenial-backports_main_binary-i386_Packages
-rw-r--r-- 1 root root 3487 Aug 4 18:55 archive.ubuntu.com_ubuntu_dists_xenial-backports_main_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 29 Nov 22 2016 archive.ubuntu.com_ubuntu_dists_xenial-backports_main_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 13516 Apr 3 23:19 archive.ubuntu.com_ubuntu_dists_xenial-backports_main_i18n_Translation-en
-rw-r--r-- 1 root root 9815 Jul 6 11:24 archive.ubuntu.com_ubuntu_dists_xenial-backports_main_source_Sources
-rw-r--r-- 1 root root 162 Feb 2 2017 archive.ubuntu.com_ubuntu_dists_xenial-backports_multiverse_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 29 Nov 23 2016 archive.ubuntu.com_ubuntu_dists_xenial-backports_multiverse_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 102193 Aug 4 21:01 archive.ubuntu.com_ubuntu_dists_xenial-backports_Release
-rw-r--r-- 1 root root 193 May 20 2016 archive.ubuntu.com_ubuntu_dists_xenial-backports_restricted_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 24619 Aug 2 13:53 archive.ubuntu.com_ubuntu_dists_xenial-backports_universe_binary-i386_Packages
-rw-r--r-- 1 root root 4961 Aug 4 18:58 archive.ubuntu.com_ubuntu_dists_xenial-backports_universe_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 2717 Aug 2 16:55 archive.ubuntu.com_ubuntu_dists_xenial-backports_universe_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 9271 Jun 21 17:50 archive.ubuntu.com_ubuntu_dists_xenial-backports_universe_i18n_Translation-en
-rw-r--r-- 1 root root 13928 Aug 2 10:54 archive.ubuntu.com_ubuntu_dists_xenial-backports_universe_source_Sources
-rw-r--r-- 1 root root 7187961 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_main_binary-i386_Packages
-rw-r--r-- 1 root root 732541 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_main_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 409405 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_main_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 3600400 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_main_i18n_Translation-en
-rw-r--r-- 1 root root 4250708 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_main_source_Sources
-rw-r--r-- 1 root root 668679 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_multiverse_binary-i386_Packages
-rw-r--r-- 1 root root 62389 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_multiverse_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 229986 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_multiverse_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 440098 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_multiverse_i18n_Translation-en
-rw-r--r-- 1 root root 727185 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_multiverse_source_Sources
-rw-r--r-- 1 root root 246846 Apr 22 2016 archive.ubuntu.com_ubuntu_dists_xenial_Release
-rw-r--r-- 1 root root 128050 Apr 15 2016 archive.ubuntu.com_ubuntu_dists_xenial_restricted_binary-i386_Packages
-rw-r--r-- 1 root root 185 Apr 6 2016 archive.ubuntu.com_ubuntu_dists_xenial_restricted_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 20517 Apr 15 2016 archive.ubuntu.com_ubuntu_dists_xenial_restricted_i18n_Translation-en
-rw-r--r-- 1 root root 23769 Apr 15 2016 archive.ubuntu.com_ubuntu_dists_xenial_restricted_source_Sources
-rw-r--r-- 1 root root 1937483 Aug 4 17:35 archive.ubuntu.com_ubuntu_dists_xenial-security_main_binary-i386_Packages
-rw-r--r-- 1 root root 79156 Aug 4 19:12 archive.ubuntu.com_ubuntu_dists_xenial-security_main_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 54689 Aug 4 19:10 archive.ubuntu.com_ubuntu_dists_xenial-security_main_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 1977441 Aug 4 16:51 archive.ubuntu.com_ubuntu_dists_xenial-security_main_i18n_Translation-en
-rw-r--r-- 1 root root 440681 Aug 4 16:51 archive.ubuntu.com_ubuntu_dists_xenial-security_main_source_Sources
-rw-r--r-- 1 root root 12874 Jul 12 01:25 archive.ubuntu.com_ubuntu_dists_xenial-security_multiverse_binary-i386_Packages
-rw-r--r-- 1 root root 159 Feb 2 2017 archive.ubuntu.com_ubuntu_dists_xenial-security_multiverse_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 29 Nov 23 2016 archive.ubuntu.com_ubuntu_dists_xenial-security_multiverse_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 5086 Jan 24 2017 archive.ubuntu.com_ubuntu_dists_xenial-security_multiverse_i18n_Translation-en
-rw-r--r-- 1 root root 2757 Jul 12 01:25 archive.ubuntu.com_ubuntu_dists_xenial-security_multiverse_source_Sources
-rw-r--r-- 1 root root 102147 Aug 4 21:01 archive.ubuntu.com_ubuntu_dists_xenial-security_Release
-rw-r--r-- 1 root root 101933 May 31 23:36 archive.ubuntu.com_ubuntu_dists_xenial-security_restricted_binary-i386_Packages
-rw-r--r-- 1 root root 199 Nov 3 2016 archive.ubuntu.com_ubuntu_dists_xenial-security_restricted_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 16164 May 31 23:36 archive.ubuntu.com_ubuntu_dists_xenial-security_restricted_i18n_Translation-en
-rw-r--r-- 1 root root 12967 May 31 23:36 archive.ubuntu.com_ubuntu_dists_xenial-security_restricted_source_Sources
-rw-r--r-- 1 root root 749774 Aug 4 06:58 archive.ubuntu.com_ubuntu_dists_xenial-security_universe_binary-i386_Packages
-rw-r--r-- 1 root root 53023 Aug 4 19:15 archive.ubuntu.com_ubuntu_dists_xenial-security_universe_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 58763 Aug 4 19:14 archive.ubuntu.com_ubuntu_dists_xenial-security_universe_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 558559 Aug 4 06:58 archive.ubuntu.com_ubuntu_dists_xenial-security_universe_i18n_Translation-en
-rw-r--r-- 1 root root 155957 Aug 4 06:58 archive.ubuntu.com_ubuntu_dists_xenial-security_universe_source_Sources
-rw-r--r-- 1 root root 41649086 Apr 22 2016 archive.ubuntu.com_ubuntu_dists_xenial_universe_binary-i386_Packages
-rw-r--r-- 1 root root 3406988 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_universe_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 7447772 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_universe_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 23426103 Apr 21 2016 archive.ubuntu.com_ubuntu_dists_xenial_universe_i18n_Translation-en
-rw-r--r-- 1 root root 35812491 Apr 22 2016 archive.ubuntu.com_ubuntu_dists_xenial_universe_source_Sources
-rw-r--r-- 1 root root 3693990 Aug 4 17:52 archive.ubuntu.com_ubuntu_dists_xenial-updates_main_binary-i386_Packages
-rw-r--r-- 1 root root 468221 Aug 4 19:19 archive.ubuntu.com_ubuntu_dists_xenial-updates_main_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 207159 Aug 4 19:17 archive.ubuntu.com_ubuntu_dists_xenial-updates_main_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 2832264 Aug 4 16:56 archive.ubuntu.com_ubuntu_dists_xenial-updates_main_i18n_Translation-en
-rw-r--r-- 1 root root 1469622 Aug 4 16:56 archive.ubuntu.com_ubuntu_dists_xenial-updates_main_source_Sources
-rw-r--r-- 1 root root 77553 Jul 27 02:38 archive.ubuntu.com_ubuntu_dists_xenial-updates_multiverse_binary-i386_Packages
-rw-r--r-- 1 root root 7615 Aug 4 19:26 archive.ubuntu.com_ubuntu_dists_xenial-updates_multiverse_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 14333 Jul 14 01:16 archive.ubuntu.com_ubuntu_dists_xenial-updates_multiverse_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 34537 Jul 27 02:38 archive.ubuntu.com_ubuntu_dists_xenial-updates_multiverse_i18n_Translation-en
-rw-r--r-- 1 root root 27886 Jul 27 02:38 archive.ubuntu.com_ubuntu_dists_xenial-updates_multiverse_source_Sources
-rw-r--r-- 1 root root 102145 Aug 4 21:01 archive.ubuntu.com_ubuntu_dists_xenial-updates_Release
-rw-r--r-- 1 root root 104003 Jul 19 00:31 archive.ubuntu.com_ubuntu_dists_xenial-updates_restricted_binary-i386_Packages
-rw-r--r-- 1 root root 156 Feb 3 2016 archive.ubuntu.com_ubuntu_dists_xenial-updates_restricted_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 16516 Jun 1 00:42 archive.ubuntu.com_ubuntu_dists_xenial-updates_restricted_i18n_Translation-en
-rw-r--r-- 1 root root 14353 Jul 18 22:20 archive.ubuntu.com_ubuntu_dists_xenial-updates_restricted_source_Sources
-rw-r--r-- 1 root root 3245482 Aug 4 17:52 archive.ubuntu.com_ubuntu_dists_xenial-updates_universe_binary-i386_Packages
-rw-r--r-- 1 root root 223772 Aug 4 19:22 archive.ubuntu.com_ubuntu_dists_xenial-updates_universe_dep11_Components-i386.yml.gz
-rw-r--r-- 1 root root 214672 Aug 4 19:21 archive.ubuntu.com_ubuntu_dists_xenial-updates_universe_dep11_icons-64x64.tar.gz
-rw-r--r-- 1 root root 1533898 Aug 4 08:09 archive.ubuntu.com_ubuntu_dists_xenial-updates_universe_i18n_Translation-en
-rw-r--r-- 1 root root 881684 Aug 4 10:44 archive.ubuntu.com_ubuntu_dists_xenial-updates_universe_source_Sources
-rw-r--r-- 1 root root 1597 Jul 18 22:30 dl.google.com_linux_earth_deb_dists_stable_main_binary-i386_Packages
-rw-r--r-- 1 root root 2136 Jul 18 22:30 dl.google.com_linux_earth_deb_dists_stable_Release
-rw-r--r-- 1 root root 1193 Jun 21 2016 dl.google.com_linux_talkplugin_deb_dists_stable_main_binary-i386_Packages
-rw-r--r-- 1 root root 2141 Jun 21 2016 dl.google.com_linux_talkplugin_deb_dists_stable_Release
-rw-r--r-- 1 root root 3571 Jul 27 20:32 download.virtualbox.org_virtualbox_debian_dists_xenial_contrib_binary-i386_Packages
-rw-r--r-- 1 root root 7877 Jul 27 20:32 download.virtualbox.org_virtualbox_debian_dists_xenial_Release
-rw-r----- 1 root root 0 Aug 4 20:53 lock
drwx------ 2 _apt root 20480 Aug 4 21:08 partial
-rw-r--r-- 1 root root 665 Oct 31 2016 ppa.launchpad.net_flexiondotorg_hal-flash_ubuntu_dists_xenial_main_binary-i386_Packages
-rw-r--r-- 1 root root 959 Oct 31 2016 ppa.launchpad.net_flexiondotorg_hal-flash_ubuntu_dists_xenial_main_i18n_Translation-en
-rw-r--r-- 1 root root 1010 Oct 31 2016 ppa.launchpad.net_flexiondotorg_hal-flash_ubuntu_dists_xenial_main_source_Sources
-rw-r--r-- 1 root root 17540 Oct 31 2016 ppa.launchpad.net_flexiondotorg_hal-flash_ubuntu_dists_xenial_Release
-rw-r--r-- 1 root root 949 Jul 22 15:25 ppa.launchpad.net_ubuntu-mate-dev_welcome_ubuntu_dists_xenial_main_binary-i386_Packages
-rw-r--r-- 1 root root 252 May 13 19:57 ppa.launchpad.net_ubuntu-mate-dev_welcome_ubuntu_dists_xenial_main_i18n_Translation-en
-rw-r--r-- 1 root root 1160 Jul 22 15:25 ppa.launchpad.net_ubuntu-mate-dev_welcome_ubuntu_dists_xenial_main_source_Sources
-rw-r--r-- 1 root root 18070 Jul 22 15:25 ppa.launchpad.net_ubuntu-mate-dev_welcome_ubuntu_dists_xenial_Release
-rw-r--r-- 1 root root 10610 Mar 21 22:44 ppa.launchpad.net_wine_wine-builds_ubuntu_dists_xenial_main_binary-i386_Packages
-rw-r--r-- 1 root root 7370 Apr 17 2016 ppa.launchpad.net_wine_wine-builds_ubuntu_dists_xenial_main_i18n_Translation-en
-rw-r--r-- 1 root root 5405 Mar 21 22:15 ppa.launchpad.net_wine_wine-builds_ubuntu_dists_xenial_main_source_Sources
-rw-r--r-- 1 root root 18064 Mar 21 22:44 ppa.launchpad.net_wine_wine-builds_ubuntu_dists_xenial_Release
-rw-r--r-- 1 root root 4872 Nov 18 2016 ppa.launchpad.net_yannubuntu_boot-repair_ubuntu_dists_xenial_main_binary-i386_Packages
-rw-r--r-- 1 root root 5314 Apr 25 2016 ppa.launchpad.net_yannubuntu_boot-repair_ubuntu_dists_xenial_main_i18n_Translation-en
-rw-r--r-- 1 root root 2342 Nov 18 2016 ppa.launchpad.net_yannubuntu_boot-repair_ubuntu_dists_xenial_main_source_Sources
-rw-r--r-- 1 root root 17541 Nov 18 2016 ppa.launchpad.net_yannubuntu_boot-repair_ubuntu_dists_xenial_Release

root@ubuntu:/# sudo apt-get update
Get:1 http://archive.ubuntu.com/ubuntu xenial InRelease [247 kB]
Ign:2 http://dl.google.com/linux/earth/deb stable InRelease
Ign:3 http://dl.google.com/linux/talkplugin/deb stable InRelease
Get:4 http://archive.canonical.com/ubuntu xenial InRelease [11.5 kB]
Ign:4 http://archive.canonical.com/ubuntu xenial InRelease
Get:5 http://download.virtualbox.org/virtualbox/debian xenial InRelease [7,877 B]
Ign:5 http://download.virtualbox.org/virtualbox/debian xenial InRelease
Get:6 http://ppa.launchpad.net/flexiondotorg/hal-flash/ubuntu xenial InRelease [17.5 kB]
Hit:7 http://dl.google.com/linux/earth/deb stable Release
Ign:6 http://ppa.launchpad.net/flexiondotorg/hal-flash/ubuntu xenial InRelease
Hit:8 http://dl.google.com/linux/talkplugin/deb stable Release
Get:9 http://ppa.launchpad.net/ubuntu-mate-dev/welcome/ubuntu xenial InRelease [18.1 kB]
Ign:9 http://ppa.launchpad.net/ubuntu-mate-dev/welcome/ubuntu xenial InRelease
Get:10 http://dl.google.com/linux/earth/deb stable Release.gpg [916 B]
Ign:10 http://dl.google.com/linux/earth/deb stable Release.gpg
Get:11 http://ppa.launchpad.net/wine/wine-builds/ubuntu xenial InRelease [18.1 kB]
Ign:11 http://ppa.launchpad.net/wine/wine-builds/ubuntu xenial InRelease
Get:12 http://dl.google.com/linux/talkplugin/deb stable Release.gpg [916 B]
Ign:12 http://dl.google.com/linux/talkplugin/deb stable Release.gpg
Get:13 http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu xenial InRelease [17.5 kB]
Ign:13 http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu xenial InRelease
Ign:1 http://archive.ubuntu.com/ubuntu xenial InRelease
Get:14 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]
Ign:14 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
Get:15 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB]
Ign:15 http://archive.ubuntu.com/ubuntu xenial-security InRelease
Get:16 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Ign:16 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
Fetched 646 kB in 4s (159 kB/s)
Reading package lists... Done
W: GPG error: http://archive.canonical.com/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://archive.canonical.com/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://download.virtualbox.org/virtualbox/debian xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://download.virtualbox.org/virtualbox/debian xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://ppa.launchpad.net/flexiondotorg/hal-flash/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://ppa.launchpad.net/flexiondotorg/hal-flash/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://ppa.launchpad.net/ubuntu-mate-dev/welcome/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://ppa.launchpad.net/ubuntu-mate-dev/welcome/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://dl.google.com/linux/earth/deb stable Release: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://dl.google.com/linux/earth/deb stable Release' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://ppa.launchpad.net/wine/wine-builds/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://ppa.launchpad.net/wine/wine-builds/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://dl.google.com/linux/talkplugin/deb stable Release: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://dl.google.com/linux/talkplugin/deb stable Release' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://archive.ubuntu.com/ubuntu xenial InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://archive.ubuntu.com/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://archive.ubuntu.com/ubuntu xenial-updates InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://archive.ubuntu.com/ubuntu xenial-updates InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://archive.ubuntu.com/ubuntu xenial-security InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://archive.ubuntu.com/ubuntu xenial-security InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://archive.ubuntu.com/ubuntu xenial-backports InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: The repository 'http://archive.ubuntu.com/ubuntu xenial-backports InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.

root@ubuntu:/# sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  linux-headers-4.4.0-83 linux-headers-4.4.0-83-generic
  linux-hwe-edge-tools-4.10.0-26 linux-image-4.4.0-83-generic
  linux-image-extra-4.4.0-83-generic linux-tools-4.10.0-26-generic
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

root@ubuntu:/# sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  linux-headers-4.4.0-83 linux-headers-4.4.0-83-generic
  linux-hwe-edge-tools-4.10.0-26 linux-image-4.4.0-83-generic
  linux-image-extra-4.4.0-83-generic linux-tools-4.10.0-26-generic
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

root@ubuntu:/# gpg2 --version
gpg (GnuPG) 2.1.11
libgcrypt 1.6.5
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: ~/.gnupg
Supported algorithms:
Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
        CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

Question information

Language:
English Edit question
Status:
Solved
For:
Ubuntu Edit question
Assignee:
No assignee Edit question
Solved by:
surendra
Solved:
2017-08-05
Last query:
2017-08-05
Last reply:
2017-08-05

Try:

sudo apt-get --reinstall install gnupg

surendra (surendra-mum) said : #2

Used the above commands by Ctrl + Alt + F1 and reinstall gnupg. Earlier used to see the login screen and able to enter password with black screen afterwards. But now its not accepting the password and showing the same login screen.

surendra (surendra-mum) said : #3

guest-yebjrd@locus-m:~$ gpg2 --version
gpg (GnuPG) 2.1.11
libgcrypt 1.6.5
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: ~/.gnupg
Supported algorithms:
Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
        CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2
guest-yebjrd@locus-m:~$

surendra (surendra-mum) said : #4

One more question that i need to verify when login as guest which shows different name each time to login as guest i.e ..... guest-yebjrd (this changes regularly). Is the system comprised.

Does the guest session work OK?

surendra (surendra-mum) said : #6

yes

surendra (surendra-mum) said : #7

But i am unable to use my partition drive as its locked.

surendra (surendra-mum) said : #8

Guest session works OK but some menu icons don't open.

OK, press CTRL + ALT + F1 and log in as your normal user then run:

sudo chown -R $USER:$USER $HOME

You don't need to change the command. The BASH variables manage themselves. Then run:

sudo apt-get clean
sudo reboot

Is it OK now?

surendra (surendra-mum) said : #10

Used the above command but now nothing works. The results of above commands shows :

chown: changing ownership of :/proc/5617/task/5617': operation not permitted
,,
''

so on with different numbers. later used the command to apt-get clean and showed :

locus@locus-m:/$ sudo apt-get clean

sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set

now nothing works even after using command:

sudo apt-get update
sudo apt-get upgarde
sudo apt-get dist-upgrade

shows the same result as above :

sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set

Tried to used Ubuntu live cd to go to root and used the above commands with below result :

root@ubuntu:/# sudo apt-get update
sudo: error in /etc/sudo.conf, line 0 while loading plugin `sudoers_policy'
sudo: /usr/lib/sudo/sudoers.so must be owned by uid 0
sudo: fatal error, unable to load plugins
root@ubuntu:/# sudo apt-get upgrade
sudo: error in /etc/sudo.conf, line 0 while loading plugin `sudoers_policy'
sudo: /usr/lib/sudo/sudoers.so must be owned by uid 0
sudo: fatal error, unable to load plugins
root@ubuntu:/# sudo apt-get dist-upgrade
sudo: error in /etc/sudo.conf, line 0 while loading plugin `sudoers_policy'
sudo: /usr/lib/sudo/sudoers.so must be owned by uid 0
sudo: fatal error, unable to load plugins
root@ubuntu:/#

Nothing works even after trying to open in advance mode in desktop.

You have botched the command and changed the ownership of more than just your home folder. This is a very specific set of permissions and ownerships which seem to have been trounced by the command.

I suggest you reinstall

surendra (surendra-mum) said : #12

oh god reinstall...its the same command i used as stated by you. nothing can be done to recover it?

Manfred Hampl (m-hampl) said : #13

What is the output of the commands

ls -l /usr/bin/sudo
ls -l /usr/lib/sudo/sudoers.so

surendra (surendra-mum) said : #14

Manfred i re-installed every thing again. Now its 14.04.5 Mate. Thanks both of you for taking some time.