Kubuntu 25.10 Beta - VirtualBox - Unable To Install Flatpaks In Discover - Error Included

[savantsavior]

Hi,

Been playing with Kubuntu 25.10 Alpha in Virtualbox.

When trying to install flatpaks in Discover, I get the following error:

Could not unmount revokefs-fuse filesystem at /var/tmp/flatpak-cache-T17PC3/org.freedesktop.Platform.GL.default-NZ7PC3: Child process exited with code 1

Any ideas?
Thanks!

SS

[oshunluvr]

AI output: Sounds like a user permission problem.

[savantsavior]

Installed 25.10 Beta into VirtualBox.
Above issue is still a problem on Beta version?

[claydoh]

It isn't an overly common problem, else there would be gobs and gobs of reports from all Ubuntu flavours and derivatives. But it seems to happen to some people here and there over the years.

But try reinstalling fuse 3 after seeing if this post is relevant:

sudo apt install fuse3 --reinstall

This is relevant for 24.04, so the issue could be different in the current release and beta and might be apparmor related, instead of fuse, which could be the cause of any permissions issues.