opensource@opensource-OptiPlex-3010:~$ sudo apt update
Ign:1 http://ug.archive.ubuntu.com/ubuntu disco InRelease
Ign:2 http://ug.archive.ubuntu.com/ubuntu disco-updates InRelease
Ign:3 http://ug.archive.ubuntu.com/ubuntu disco-backports InRelease
Err:4 http://ug.archive.ubuntu.com/ubuntu disco Release
  404  Not Found [IP: 197.155.77.2 80]
Err:5 http://ug.archive.ubuntu.com/ubuntu disco-updates Release
  404  Not Found [IP: 197.155.77.2 80]
Err:6 http://ug.archive.ubuntu.com/ubuntu disco-backports Release
  404  Not Found [IP: 197.155.77.2 80]
Hit:7 http://ppa.launchpad.net/linuxuprising/java/ubuntu disco InRelease
Ign:8 http://security.ubuntu.com/ubuntu disco-security InRelease
Err:9 http://security.ubuntu.com/ubuntu disco-security Release
  404  Not Found [IP: 91.189.88.142 80]
Reading package lists... Done
E: The repository 'http://ug.archive.ubuntu.com/ubuntu disco 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://ug.archive.ubuntu.com/ubuntu disco-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://ug.archive.ubuntu.com/ubuntu disco-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.
E: The repository 'http://security.ubuntu.com/ubuntu disco-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.
opensource@opensource-OptiPlex-3010:~$