Why I am getting error "ignoring invalid group name" on execution of "dconf update" command ?

Issue

• When trying to create a new profile in /etc/dconf/, with following content:

# cat /etc/dconf/db/local.d/03-displaybuttons
[/org/gnome/shell/overrides]
button-layout=':minimize,maximize,close'

• The "dconf update" command gives following error :

# dconf update
/etc/dconf/db/local.d/03-displaybuttons: ignoring invalid group name: /org/gnome/shell/overrides
(dconf-editor:13200): dconf-WARNING **: Need to handle writability changes
(dconf-editor:13200): dconf-WARNING **: Need to handle writability changes