Permission denied for chattr +i command

I try to make the following file immutable by issuing the chattr +i command but get the permission denied error.

See: Mobile VPN usage, ipv6 not routed and DNS leaks:

I use devel-su as and are a root user.

The file is /var/run/connman/resolv.conf

reboot or restart home and rry again - it’s because it’s engaged in some kind of dynamic/tmp activity…

Awesome, indeed a reboot and from the phone terminal (not ssh) and it worked. Thanks again!