AppImage Error: SUID Not Configured Correctly

[KawaneRio]

Duplicate of #15 ; However, running sudo sysctl kernel.unprivileged_userns_clone=1 and --no-sandbox did not work.

kawanerio@KawaneLinux:~/Downloads$ /home/kawanerio/Downloads/PanWriter-0.8.9.AppImage 
[847671:0711/182008.205108:FATAL:setuid_sandbox_host.cc(163)] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /tmp/.mount_PanWriGdG5Au/chrome-sandbox is owned by root and has mode 4755.
Trace/breakpoint trap (コアダンプ)

Tried running with --no-sandbox parameter, but now the application just hangs:

kawanerio@KawaneLinux:~/Downloads$ /home/kawanerio/Downloads/PanWriter-0.8.9.AppImage --no-sandbox
Error loading or parsing YAML file.ENOENT: no such file or directory, open '/home/kawanerio/.config/PanWriterUserData/settings.yaml'
Checking for update
Generated new staging user ID: 6a9ceadd-0f0c-5b76-b1e6-831929f7a687
Update for version 0.8.9 is not available (latest version: 0.8.9, downgrade is disallowed).
checkForUpdatesAndNotify called, downloadPromise is null

Upon visiting issue #15 , I've ran the following command: sudo sysctl kernel.unprivileged_userns_clone=1, however, the AppImage still fails to launch:

kawanerio@KawaneLinux:~/Downloads sudo sysctl kernel.unprivileged_userns_clone=1
[sudo] kawanerio のパスワード: 
kernel.unprivileged_userns_clone = 1
kawanerio@KawaneLinux:~/Downloads$ /home/kawanerio/Downloads/PanWriter-0.8.9.AppImage 
[849260:0711/182524.771993:FATAL:setuid_sandbox_host.cc(163)] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /tmp/.mount_PanWrilgmgEq/chrome-sandbox is owned by root and has mode 4755.
Trace/breakpoint trap (コアダンプ)

Tried running with --no-sandbox parameter once again after the sudo sysctl kernel.unprivileged_userns_clone=1, but still hangs:

kawanerio@KawaneLinux:~/Downloads$ /home/kawanerio/Downloads/PanWriter-0.8.9.AppImage --no-sandbox
Error loading or parsing YAML file.ENOENT: no such file or directory, open '/home/kawanerio/.config/PanWriterUserData/settings.yaml'
Checking for update
Update for version 0.8.9 is not available (latest version: 0.8.9, downgrade is disallowed).
checkForUpdatesAndNotify called, downloadPromise is null

I am using Ubuntu.

[mb21]

I'm not very familiar with AppImage intricacies. Do previous versions of PanWriter work?

[lproven]

This affects me too. I have now updated but I think it also affected Panwriter 0.8.6.

It is a known issue with sandboxing changes in Ubuntu 24.04 but that affects multiple other downstream distros, including Linux Mint, Linux Lite, Elementary OS, and others.

Examples:

https://askubuntu.com/questions/1512287/obsidian-appimage-the-suid-sandbox-helper-binary-was-found-but-is-not-configu

https://ubuntu-mate.community/t/noble-numbat-two-appimage-apps-fail-with-sandbox-error/27994

laurent22/joplin#11251