I’m facing error messages when I launch apt update :
greg@greg-NUC11TNKv7:~$ sudo apt update
Atteint :1 http://mirrors.ircam.fr/pub/ubuntu/archive noble InRelease
Atteint :2 http://mirrors.ircam.fr/pub/ubuntu/archive noble-updates InRelease
Atteint :3 https://dl.winehq.org/wine-builds/ubuntu jammy InRelease
Atteint :4 http://mirrors.ircam.fr/pub/ubuntu/archive noble-security InRelease
Atteint :5 http://mirrors.ircam.fr/pub/ubuntu/archive noble-backports InRelease
Réception de :6 https://esm.ubuntu.com/apps/ubuntu noble-apps-security InRelease [7 532 B]
Réception de :7 https://esm.ubuntu.com/apps/ubuntu noble-apps-updates InRelease [7 468 B]
Atteint :8 https://ppa.launchpadcontent.net/sane-project/sane-release/ubuntu noble InRelease
Réception de :9 https://esm.ubuntu.com/infra/ubuntu noble-infra-security InRelease [7 462 B]
Réception de :10 https://esm.ubuntu.com/infra/ubuntu noble-infra-updates InRelease [7 461 B]
Atteint :11 https://debian.qgis.org/debian jammy InRelease
29,9 ko réceptionnés en 1s (44,8 ko/s)
Lecture des listes de paquets... Fait
Construction de l'arbre des dépendances... Fait
Lecture des informations d'état... Fait
2 paquets peuvent être mis à jour. Exécutez « apt list --upgradable » pour les voir.
N: Missing Signed-By in the sources.list(5) entry for 'https://esm.ubuntu.com/apps/ubuntu'
N: Missing Signed-By in the sources.list(5) entry for 'https://esm.ubuntu.com/apps/ubuntu'
N: Missing Signed-By in the sources.list(5) entry for 'https://esm.ubuntu.com/infra/ubuntu'
N: Missing Signed-By in the sources.list(5) entry for 'https://esm.ubuntu.com/infra/ubuntu'
greg@greg-NUC11TNKv7:~$
As you can see, I have “Missing Signed-By…” error messages. I have this message since I updated Ubunut 22.04 to 24.04.
Do you have an Ubuntu Pro subscription?If yes keep reading,if no then what follows won’t help.
Open up Software&Updates then open Ubuntu Pro,is Pro enabled?If not enable it and under Security are the three switches toggled on?If not toggle them on and try updating again.
Those are only "N"otes, not warnings or errors. It just means that repository is signed by a globally-trusted APT key (stored somewhere in /etc/apt/trusted.gpg.d) instead of being signed by a key specific to that repository. You can safely ignore those notes.
Addressing the notes would involve manually specifying which specific key in /etc/apt/trusted.gpg.d is used to sign those repositories. To start figuring out how/where to do that would involve seeing the output from running the following commands in Terminal -
grep -F -r 'https://esm.ubuntu.com/' /etc/apt/sources.list.d
ls /etc/apt/trusted.gpg.d/
ls /var/lib/apt/lists/esm.ubuntu.com_*InRelease