portal_error.txt

Your Flatpak version does not support a feature needed for this Chromium Flatpak
to run. This generally happens when your distribution has unprivileged user
namespaces disabled.

========== FOR DEBIAN FAMILY USERS ==========

If the distro you are currently using is Debian or a derivative, you can run the
following commands as root (you can enter a root shell via 'sudo -i'):

dpkg-statoverride --update --add root root 0755 /usr/bin/bwrap
echo kernel.unprivileged_userns_clone=1 > /etc/sysctl.d/50-bubblewrap.conf
sudo sysctl -w kernel.unprivileged_userns_clone=1

========== FOR OTHER DISTROS =========

If you installed a "hardened" security kernel, these also usually disable
unprivileged user namespaces. They can be re-enabled by running the following
as root (you can enter a root shell via 'sudo -i'):

echo kernel.unprivileged_userns_clone=1 > /etc/sysctl.d/50-bubblewrap.conf
sudo sysctl -w kernel.unprivileged_userns_clone=1

If 'ls -l /usr/bin/bwrap' contains 'rws', then bwrap is also setuid. This can be
removed, if present, via:

sudo chmod u-s /usr/bin/bwrap

However, note that the permissions may be overridden on the next update of your
distro's bubblewrap package.