@zaasmi said in Running “apt-get update” returns an error “apt-secure(8)”: E: The repository ‘http://asi-fs-n.contabo.net/ubuntu cosmic Release’ no longer has 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://asi-fs-n.contabo.net/ubuntu cosmic-updates Release’ no longer has 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://asi-fs-n.contabo.net/ubuntu cosmic-backports Release’ no longer has 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://security.ubuntu.com/ubuntu cosmic-security Release’ no longer has 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. Error executing command, exiting Disable in source list error list and runs sudo apt-get update sudo apt-get upgrade sudo apt-get dist-upgrade For Nodejs Update following command will work! curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash - sudo apt-get install -y nodejs