I know this question has been brought up ad nauseam, but I want to be sure I make the right changes to fix it. I'm pretty sure I need to change some of the settings in Software & Updates, but which ones? Or is there something else I need to resolve? Here's the terminal message that displays when I run sudo apt-get update along with the Software & Updates menu.
edit: included text.
nicholas@klaus:~$ sudo apt-get update
[sudo] password for nicholas:
Hit:1 http://repo.steampowered.com/steam precise InRelease
Ign:2 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Hit:4 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:5 http://packages.microsoft.com/repos/vscode stable InRelease
Hit:6 http://dl.google.com/linux/chrome/deb stable Release
Get:7 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Hit:8 https://dl.winehq.org/wine-builds/ubuntu bionic InRelease
Ign:9 http://ppa.launchpad.net/mjblenner/ppa-hal/ubuntu bionic InRelease
Hit:10 http://repository.spotify.com stable InRelease
Err:12 http://ppa.launchpad.net/mjblenner/ppa-hal/ubuntu bionic Release
404 Not Found [IP: 91.189.95.83 80]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/mjblenner/ppa-hal/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.
