Flatpak Fails to Function in Ubuntu 25.10 Due to AppArmor Issue
A critical bug has been identified in the latest release of Ubuntu 25.10, which prevents Flatpak from functioning properly. The issue is caused by a lack of privileges in the AppArmor profile for fusermount3, a tool relied upon by Flatpak to mount and unmount filesystems.
According to OMG Ubuntu, users who have installed Ubuntu's "Questing Quokka" release are experiencing difficulties installing Flatpaks from the command line. The error message reads: "could not unmount revokefs-fuse filesystem" followed by "Child process exited with code 1."
The bug was reported on Launchpad in early September and has been marked as critical, indicating that it will be prioritized for a fix. Although there is no timeframe for a resolution, an updated AppArmor package was pushed to the "questing-proposed" archive for testing just last Friday.
"We're aware of the issue and are working on a solution," said a spokesperson for Canonical, the company behind Ubuntu. "We apologize for any inconvenience this may have caused our users."
The bug affects users who rely on Flatpak to install software from Flathub, a popular repository of applications for Linux systems. The inability to install Flatpaks can be frustrating for those who want to kit out their Ubuntu system with their favorite software.
AppArmor is a security tool that enforces Ubuntu's security policies for apps. It works by restricting the actions that an application can perform on the system, thereby preventing potential security threats. However, in this case, the AppArmor profile for fusermount3 lacks the necessary privileges to function properly, leading to the error.
The bug is not unique to Ubuntu 25.10 and has been reported by users of previous releases as well. However, it appears that the issue was not resolved in time for the latest release.
As the developers work on a fix, users are advised to keep an eye on the "questing-proposed" archive for updates. In the meantime, those who rely on Flatpak may need to consider alternative solutions or wait patiently for the bug to be resolved.
The development team is expected to provide more information on the status of the fix in the coming days.
*Reporting by News.*
