title: Ububtu 18.04 sudo apt-get update is not working
body: <p>I'm getting following errors while running sudo apt-get update command in my system(ubuntu 18.04) and also not able to install any new application:-</p>
  
  <pre><code>$ sudo apt-get update
  Hit:1 http://repo.mysql.com/apt/ubuntu bionic InRelease
  Hit:2 http://linux.teamviewer.com/deb stable InRelease                         
  Ign:3 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.2 InRelease      
  Hit:4 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.2 Release        
  Get:5 http://sfo1.mirrors.digitalocean.com/mariadb/repo/10.2/debian jessie InRelease [3,263 B]
  Ign:6 http://dl.google.com/linux/chrome/deb stable InRelease                   
  Hit:7 https://repo.skype.com/deb stable InRelease                              
  Hit:9 http://ppa.launchpad.net/flexiondotorg/hal-flash/ubuntu bionic InRelease 
  Ign:11 http://extras.ubuntu.com/ubuntu trusty InRelease                        
  Hit:12 http://security.ubuntu.com/ubuntu trusty-security InRelease             
  Ign:13 http://archive.ubuntu.com/ubuntu artful InRelease                       
  Ign:14 http://archive.canonical.com/ubuntu trusty InRelease                    
  Err:5 http://sfo1.mirrors.digitalocean.com/mariadb/repo/10.2/debian jessie InRelease
    The following signatures were invalid: 199369E5404BD5FC7D2FE43BCBCB082A1BB943DB
  Hit:15 http://dl.google.com/linux/chrome/deb stable Release                    
  Hit:17 http://ppa.launchpad.net/linuxuprising/java/ubuntu bionic InRelease     
  Get:18 http://extras.ubuntu.com/ubuntu trusty Release [11.9 kB]                
  Hit:19 http://archive.canonical.com/ubuntu trusty Release                      
  Ign:20 http://archive.ubuntu.com/ubuntu artful-updates InRelease               
  Get:22 http://extras.ubuntu.com/ubuntu trusty Release.gpg [72 B]               
  Ign:23 http://archive.ubuntu.com/ubuntu artful-security InRelease              
  Hit:25 http://ppa.launchpad.net/oibaf/graphics-drivers/ubuntu bionic InRelease 
  Hit:8 https://downloads.mariadb.com/MariaDB/mariadb-10.3/repo/ubuntu bionic InRelease
  Ign:26 http://archive.ubuntu.com/ubuntu artful-backports InRelease             
  Hit:28 http://archive.ubuntu.com/ubuntu bionic InRelease                       
  Ign:29 https://dl.bintray.com/rabbitmq/debian bionic InRelease                 
  Ign:22 http://extras.ubuntu.com/ubuntu trusty Release.gpg                      
  Err:21 http://www.getdeb.net/ubuntu xenial-getdeb InRelease                    
    403  Forbidden [IP: 143.95.32.90 80]
  Ign:30 http://ppa.launchpad.net/ondrej/mysql-5.6/ubuntu bionic InRelease       
  Ign:31 http://archive.ubuntu.com/ubuntu trusty InRelease                       
  Get:32 https://dl.bintray.com/rabbitmq/debian bionic Release [74.5 kB]         
  Hit:33 http://archive.ubuntu.com/ubuntu trusty-updates InRelease               
  Hit:16 https://downloads.mariadb.com/Tools/ubuntu bionic InRelease             
  Hit:34 http://archive.ubuntu.com/ubuntu trusty-backports InRelease             
  Hit:35 http://ppa.launchpad.net/ondrej/php/ubuntu bionic InRelease             
  Hit:36 http://archive.ubuntu.com/ubuntu bionic-updates InRelease               
  Hit:37 http://ppa.launchpad.net/openjdk-r/ppa/ubuntu bionic InRelease          
  Err:38 http://archive.ubuntu.com/ubuntu artful Release                         
    404  Not Found [IP: 2001:67c:1360:8001::23 80]
  Err:39 http://archive.ubuntu.com/ubuntu artful-updates Release                 
    404  Not Found [IP: 2001:67c:1360:8001::23 80]
  Err:40 http://archive.ubuntu.com/ubuntu artful-security Release                
    404  Not Found [IP: 2001:67c:1360:8001::23 80]
  Hit:41 http://ppa.launchpad.net/phpmyadmin/ppa/ubuntu bionic InRelease    
  Err:43 http://archive.ubuntu.com/ubuntu artful-backports Release               
    404  Not Found [IP: 2001:67c:1360:8001::23 80]
  Hit:44 http://archive.ubuntu.com/ubuntu trusty Release                         
  Ign:45 http://ppa.launchpad.net/pmiller-opensource/ppa/ubuntu bionic InRelease
  Hit:46 http://ppa.launchpad.net/umang/indicator-stickynotes/ubuntu bionic InRelease
  Hit:48 http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease       
  Err:49 http://ppa.launchpad.net/ondrej/mysql-5.6/ubuntu bionic Release         
    404  Not Found [IP: 2001:67c:1560:8008::15 80]
  Err:50 http://ppa.launchpad.net/pmiller-opensource/ppa/ubuntu bionic Release
    404  Not Found [IP: 2001:67c:1560:8008::15 80]
  Reading package lists... Done                                
  W: GPG error: http://sfo1.mirrors.digitalocean.com/mariadb/repo/10.2/debian jessie InRelease: The following signatures were invalid: 199369E5404BD5FC7D2FE43BCBCB082A1BB943DB
  E: The repository 'http://sfo1.mirrors.digitalocean.com/mariadb/repo/10.2/debian jessie InRelease' is not signed.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  W: GPG error: http://extras.ubuntu.com/ubuntu trusty Release: The following signatures were invalid: C47415DFF48C09645B78609416126D3A3E5C1192
  E: The repository 'http://extras.ubuntu.com/ubuntu trusty Release' is not signed.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  E: Failed to fetch http://archive.getdeb.net/ubuntu/dists/xenial-getdeb/InRelease  403  Forbidden [IP: 143.95.32.90 80]
  E: The repository 'http://archive.getdeb.net/ubuntu xenial-getdeb InRelease' is not signed.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'http://downloads.mariadb.com/MariaDB/mariadb-10.3/repo/ubuntu bionic InRelease' doesn't support architecture 'i386'
  N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'http://downloads.mariadb.com/Tools/ubuntu bionic InRelease' doesn't support architecture 'i386'
  E: The repository 'http://archive.ubuntu.com/ubuntu artful Release' does not have a Release file.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  E: The repository 'http://archive.ubuntu.com/ubuntu artful-updates Release' does not have a Release file.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  E: The repository 'http://archive.ubuntu.com/ubuntu artful-security Release' does not have a Release file.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  E: The repository 'http://archive.ubuntu.com/ubuntu artful-backports Release' does not have a Release file.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  W: Target Packages (universe/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Packages (universe/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Packages (universe/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Translations (universe/i18n/Translation-en_IN) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Translations (universe/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11 (universe/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11 (universe/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11-icons-small (universe/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11-icons (universe/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target CNF (universe/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target CNF (universe/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  E: The repository 'http://ppa.launchpad.net/ondrej/mysql-5.6/ubuntu bionic Release' does not have a Release file.
  N: Updating from such a repository can't be done securely and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  E: The repository 'http://ppa.launchpad.net/pmiller-opensource/ppa/ubuntu bionic Release' does not have a Release file.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  W: Target Packages (universe/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Packages (universe/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Packages (universe/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Translations (universe/i18n/Translation-en_IN) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target Translations (universe/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11 (universe/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11 (universe/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11-icons-small (universe/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target DEP-11-icons (universe/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target CNF (universe/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  W: Target CNF (universe/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list:12
  </code></pre>
  
  <p>Please suggest the steps need to perform to resolve this problem. </p>
  
  <p>These errors while running sudo apt-get update command in my system(ubuntu 18.04) and also not able to install any new application.</p>