Missing Signed-By in the sources.list(5) entry for After Update

General Help
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1

Last week I installed fuse to be able to run a dwg to dxf converter but it unfortunately disabled much of the features on the desktop. When I rebooted, I couldn't enter Zorin (went to tty4 with Alt+F4). Anyway I found a solution here where I kinda reinstalled the desktop from tty4:

systemctl start NetworkManager
apt install ubuntu-desktop
reboot

(I think I replaced the second line with

sudo apt-get install gnome-shell ubuntu-gnome-desktop

because I got saw this solution)

I was able to get back into Zorin but the whole desktop (font and dimensions were more like regular Ubuntu, see screenshot). Also some of the software was acting funny. VLC wasn't able to show videos. I can't uninstall it from the software app. I installed it again and it works but now I have 2 VLCs :')
Same for KdenLive.

I ran sudo apt update and I got the following:

E: The repository 'https://ppa.launchpadcontent.net/noobslab/themes/ubuntu noble 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.
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/stable'
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/patches'
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/apps'
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/drivers'

When I ran this to check if I have the 4 files as recommended in other solutions:
sudo cp zorin.list.distUpgrade zorin.list.save zorin.sources zorin.sources.save ~/Desktop
I got only two files on my desktop: zorin.list.distUpgrade and zorin.sources.
and I got the following message:

cp: cannot stat 'zorin.list.save': No such file or directory
cp: cannot stat 'zorin.sources.save': No such file or directory

When I ran cat /etc/apt/sources.list
I got this: # Ubuntu sources have moved to /etc/apt/sources.list.d/ubuntu.sources

When I ran this instead cat /etc/apt/sources.list.d/ubuntu.sources
I got the following:

Types: deb
URIs: http://eg.archive.ubuntu.com/ubuntu/
Suites: noble noble-updates noble-backports
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg

Types: deb
URIs: http://security.ubuntu.com/ubuntu
Suites: noble-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg

I was trying to find solutions, some suggested installing xdg-desktop-portal but I'm not sure if it is related.

I don't know how to solve this but I prefer a solution that does not mess up my desktop. Any help is appreciated.

Screenshot from 2026-07-16 02-39-52
Screenshot from 2026-07-16 02-39-521920×1080 226 KB

2

The command you ran installed the Ubuntu Desktop Environment, replacing the Zorin Core desktop environment.
I think your first step should be to restore the Zorin Desktop:

sudo apt install --reinstall zorin-os-desktop

1 Like
3

Thank you for your response! It worked for restoring Zorin's core desktop :slight_smile:

However for sudo apt update I still get the following:

E: The repository 'https://ppa.launchpadcontent.net/noobslab/themes/ubuntu noble 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.
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/stable'
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/patches'
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/apps'
N: Missing Signed-By in the sources.list(5) entry for 'https://packages.zorinos.com/drivers'

The command to copy the 4 files to the desktop (sudo cp zorin.list.distUpgrade zorin.list.save zorin.sources zorin.sources.save ~/Desktop) still yields:

cp: cannot stat 'zorin.list.distUpgrade': No such file or directory
cp: cannot stat 'zorin.list.save': No such file or directory
cp: cannot stat 'zorin.sources': No such file or directory
cp: cannot stat 'zorin.sources.save': No such file or directory

and only zorin.list.distUpgrade and zorin.sources are copied to the desktop.

4

I am not sure where you are getting that command from, but I do not see any obvious way it could help you...

You must remove this repository to get rid of this warning. Noobslabs has apparently been abandoned and has no files for Noble.
However... this does not mean you cannot use their themes.
Just go to their Launchpad and download the cosmic .deb package for your desired theme and then double click it to install.

Can you please try this solution?

1 Like
5

Is something missing at the end? Do you mean that thread?

In the solution of the thread @Ponce-De-Leon saved the files on the desktop (as backup).

@bala_akhalak Were you in the sources folder when you entered the command to copy the files?
It could also be a language Problem if your desktop is translated into your language, then try to use the translated word in the path instead of desktop, e.g. in German it is Schreibtisch.

1 Like
6

I hit ctl+v, I swear...