Iridium Browser Install Fatal Error

A fter installing Iridium Browser, running the program first time I got the following error:] No usable sandbox!  Update your kernel or see for more information on developing with the SUID sandbox.

On Debian userns is compiled-in but disabled by default. There's a Debian-specific patch to the kernel that adds sysctl knob: kernel.unprivileged_userns_clone. You have to add a new entry in /etc/sysctl.d and set it to 1

You can do it manually by typing:

# echo 1 > /proc/sys/kernel/unprivileged_userns_clone 

This is a temporary solution and only works until reboot.

For a permanent solution:

# echo 'kernel.unprivileged_userns_clone=1' > /etc/sysctl.d/00-local-userns.conf 

# service procps restart

After issuing the above command and launching Iridium, it runs flawlessly.