[Bug]: Ubuntu 24.04 hanging Signal Desktop 7.81.0

[IamSkoopy]

What happened?

I am using signal desktop since years.
Starting in September (I don't recall the version) my system started hanging completely when using signal.
I open the signal app, I get a flikkering signal, and the complete system comes to a halt. I am only able to do a hardware reboot.

I did some reinstalls.
I did some housekeeping of my system... cleaning virus scanning etc.
Almost 3 months later still having the same issue. I did not encounter problems with this pc, I using it daily.

I am using the official ubuntu Snap version on
Distributor ID: Ubuntu
Description: Ubuntu 24.04.3 LTS
Release: 24.04
Codename: noble

What should have happened?

A not hanging PC

Output of snap info $snap_name

snap info signal-desktop
name:      signal-desktop
summary:   Speak Freely - Private Messenger
publisher: Snapcrafters✪
store-url: https://snapcraft.io/signal-desktop
contact:   https://github.com//snapcrafters/signal-desktop/issues
license:   AGPL-3.0-only
description: |
  **Note: To use the Signal desktop app, you must first install Signal on your phone.**
  
  Millions of people use Signal every day for free and instantaneous communication anywhere in the
  world. Send and receive high-fidelity messages, participate in HD voice/video calls, and explore a
  growing set of new features that help you stay connected. Signal's advanced privacy-preserving
  technology is always enabled, so you can focus on sharing the moments that matter with the people
  who matter to you.
  
  - Say anything - State-of-the-art end-to-end encryption (powered by the open source Signal
  Protocol™) keeps your conversations secure. Privacy isn't an optional mode; it's just the way that
  Signal works. Every message, every call, every time.
  - Go fast - Messages are delivered quickly and reliably, even on slow networks. Signal is
  optimized to operate in the most constrained environment possible.
  - Feel free - Signal is a completely independent 501c3 nonprofit. Development is supported by
  users like you. No advertisements. No trackers. No kidding.
  - Be yourself - You can use your existing phone number and address book to securely communicate
  with your friends.
  - Speak up - Whether they live across town or across the ocean, Signal's enhanced audio and video
  quality will make your friends and family feel closer.
  - Whisper in the shadows - Switch to the dark theme if you refuse to see the light.
  
  **Minimize to tray**
  
  Per the request of the Signal developers, this snap does not use the system tray by default. This
  is disabled by default per the request of the Signal developers, because system tray support is
  not stable. Set to `false`, Signal will stop when you close it and will not have a system tray
  icon. You can enable it by running the following command.
  
      snap set signal-desktop tray-icon=true
  
  
  **Are you having issues?**
  
  Let us know by creating a new issue here: https://github.com/snapcrafters/signal-desktop/issues
  
  **Authors**
  
  This snap is maintained by the Snapcrafters community, and is not necessarily endorsed or
  officially maintained by the upstream developers.
commands:
  - signal-desktop
snap-id:      r4LxMVp7zWramXsJQAKdamxy6TAWlaDD
tracking:     latest/stable
refresh-date: today at 16:16 CET
channels:
  latest/stable:    7.81.0 2025-12-04 (857) 258MB -
  latest/candidate: 7.81.0 2025-12-04 (857) 258MB -
  latest/beta:      ↑                             
  latest/edge:      ↑                             
installed:          7.81.0            (857) 258MB -

Output of snap connections $snap_name

snap connections signal-desktop
Interface               Plug                                   Slot                            Notes
audio-playback          signal-desktop:audio-playback          :audio-playback                 -
audio-record            signal-desktop:audio-record            :audio-record                   -
browser-support         signal-desktop:browser-support         :browser-support                -
camera                  signal-desktop:camera                  :camera                         -
content[gnome-46-2404]  signal-desktop:gnome-46-2404           gnome-46-2404:gnome-46-2404     -
content[gpu-2404]       signal-desktop:gpu-2404                mesa-2404:gpu-2404              -
content[gtk-3-themes]   signal-desktop:gtk-3-themes            gtk-common-themes:gtk-3-themes  -
content[icon-themes]    signal-desktop:icon-themes             gtk-common-themes:icon-themes   -
content[sound-themes]   signal-desktop:sound-themes            gtk-common-themes:sound-themes  -
desktop                 signal-desktop:desktop                 :desktop                        -
desktop-legacy          signal-desktop:desktop-legacy          :desktop-legacy                 -
gsettings               signal-desktop:gsettings               :gsettings                      -
home                    signal-desktop:home                    :home                           -
network                 signal-desktop:network                 :network                        -
opengl                  signal-desktop:opengl                  :opengl                         -
removable-media         signal-desktop:removable-media         -                               -
screen-inhibit-control  signal-desktop:screen-inhibit-control  :screen-inhibit-control         -
unity7                  signal-desktop:unity7                  :unity7                         -
wayland                 signal-desktop:wayland                 :wayland                        -
x11                     signal-desktop:x11                     :x11                            -

Output of snap version

snap          2.72+ubuntu24.04
snapd         2.72+ubuntu24.04
series        16
ubuntu        24.04
kernel        6.8.0-88-generic
architecture  amd64

Relevant log output

[   12.445918] systemd-journald[527]: File /var/log/journal/30d910320088423ea446af51d04f361e/user-1000.journal corrupted or uncleanly shut down, renaming and replacing.
[   12.476091] kernel: kauditd_printk_skb: 250 callbacks suppressed
[   12.476096] kernel: audit: type=1400 audit(1765193664.426:262): apparmor="DENIED" operation="capable" class="cap" profile="/usr/sbin/cupsd" pid=2123 comm="cupsd" capability=12  capname="net_admin"
[   12.485384] kernel: audit: type=1400 audit(1765193664.435:263): apparmor="DENIED" operation="open" class="file" profile="snap.canonical-livepatch.canonical-livepatchd" name="/proc/2125/mountinfo" pid=2125 comm="canonical-livep" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
[   12.607022] kernel: usb 2-1.2: reset high-speed USB device number 3 using ehci-pci
[   13.208960] kernel: audit: type=1326 audit(1765193665.158:264): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=snap.cups.cupsd pid=2343 comm="cupsd" exe="/snap/cups/1130/sbin/cupsd" sig=0 arch=c000003e syscall=93 compat=0 ip=0x74a9f7e59b0b code=0x50000

Teminal output of app

[jnsgruk]

Hi, can you please run the app from the Terminal and post the output?

Open terminal and run signal-desktop :)

[IamSkoopy]

signal-desktop
NODE_ENV production
NODE_CONFIG_DIR /snap/signal-desktop/857/opt/Signal/resources/app.asar/config
NODE_CONFIG {}
ALLOW_CONFIG_MUTATIONS undefined
HOSTNAME HP-Compaq-8200-Elite-CMT-Ubuntu22
NODE_APP_INSTANCE undefined
SUPPRESS_NO_CONFIG_WARNING undefined
SIGNAL_ENABLE_HTTP undefined
userData: /home/guidodb/snap/signal-desktop/857/.config/Signal
Error org.freedesktop.DBus.Error.Failed: cannot find desktop file "/var/lib/snapd/desktop/applications/signal-desktop_signal.desktop"
Error org.freedesktop.DBus.Error.Failed: cannot find desktop file "/var/lib/snapd/desktop/applications/signal-desktop_signal.desktop"
Gtk-Message: 16:58:32.904: Not loading module "atk-bridge": The functionality is provided by GTK natively. Please try to not load it.
(node:4192) [DEP0180] DeprecationWarning: fs.Stats constructor is deprecated.
(Use signal-desktop --trace-deprecation ... to show where the warning was created)
[4192:1208/165833.686417:error:net/disk_cache/simple/simple_version_upgrade.cc:114] Disk cache backend fake index file has wrong size.
[4192:1208/165833.686486:error:net/disk_cache/simple/simple_version_upgrade.cc:114] Disk cache backend fake index file has wrong size.
[4415:1208/165833.702203:error:net/disk_cache/simple/simple_version_upgrade.cc:114] Disk cache backend fake index file has wrong size.
[4415:1208/165833.705026:error:net/disk_cache/simple/simple_version_upgrade.cc:114] Disk cache backend fake index file has wrong size.
[4415:1208/165833.705184:error:net/disk_cache/simple/simple_backend_impl.cc:749] Simple Cache Backend: wrong file structure on disk: 10 path: /home/guidodb/snap/signal-desktop/857/.config/Signal/Cache/Cache_Data
[4192:1208/165834.009762:error:net/disk_cache/blockfile/backend_impl.cc:1972] Invalid file magic
[4192:1208/165834.010250:error:net/disk_cache/blockfile/backend_impl.cc:1972] Invalid file magic
[4192:1208/165834.010434:error:net/disk_cache/blockfile/backend_impl.cc:1972] Invalid file magic
[4192:1208/165834.015753:error:dbus/object_proxy.cc:573] Failed to call method: org.freedesktop.login1.Manager.Inhibit: object_path= /org/freedesktop/login1: org.freedesktop.DBus.Error.AccessDenied: An AppArmor policy prevents this sender from sending this message to this recipient; type="method_call", sender=":1.97" (uid=1000 pid=4192 comm="/snap/signal-desktop/857/opt/Signal/signal-desktop" label="snap.signal-desktop.signal-desktop (enforce)") interface="org.freedesktop.login1.Manager" member="Inhibit" error name="(unset)" requested_reply="0" destination="org.freedesktop.login1" (uid=0 pid=1425 comm="/usr/lib/systemd/systemd-logind" label="unconfined")
^CRender process is gone: Error: Reason: killed, Exit Code: 2
at EventEmitter. (/snap/signal-desktop/857/opt/Signal/resources/app.asar/app/global_errors.main.js:94:7)
at EventEmitter.emit (node:events:519:28)
at WebContents. (node:electron/js2c/browser_init:2:89526)
at WebContents.emit (node:events:519:28)

[IamSkoopy]

[jnsgruk]

It looks like there is some erroring over a corrupt file, though I don't think that would cause the symptoms you describe.

Could you try the following, which will completely remove signal and all it's cache/config and reinstall it:

sudo snap remove signal-desktop --purge
sudo snap install signal-desktop

[IamSkoopy]

This time I managed to start the application. But it had regular freezes.
when moving the window around I got following views.
after several seconds, Signal was again responsive,
when all the messages were downloaded, I was able to look into some threads, interrupted by many freezes. But this time only signal desktop was freezing, not the complete PC.
Till I got a full hang, after several minutes I decided to go for a hard reboot.
Maybe a memory leak kicks in?
Although it had already a problem before I made the link with my mobile (see the screenshot).
As said I have only seen this problem with Signal desktop. I have no problem with any other application on this device.

[olivercalder]

This sounds like it might be a problem with your graphics drivers, which are provided by the mesa-2404 content snap.

Today, I had what looked like the Signal Desktop snap "broke", but it was actually a problem with mesa-2404. I needed mesa 25 to have graphics work on my AMD 9000 series graphics card, and at install time the latest track of mesa-2404 was still on mesa 24, so I have been tracking the latest/beta/kisak channel instead. But today a build was released to latest/beta/kisak which broke graphics for me, causing Signal Desktop to no longer appear when launched. My fix was to refresh to the latest/stable channel of mesa-2404.

A hard lockup seems like it could be a graphics driver problem as well, if the drivers fully crash. Perhaps it's worth checking: could you please provide the output of:

snap info mesa-2404

Thanks!