Hi Hannie,
Thanks for giving this a look, and for being so detail-oriented.
While Ubuntu 16.04 is an LTS release for Ubuntu, it's a rather old version
to be troubleshooting against for docs. Could you see if you have the same
question on Ubuntu 17.10?
Not seeing the curtain also makes me wonder
While testing The Lock Screen in Ubuntu-gnome 16.04, I noticed that I do
not get the lock screen curtain, as described in *gnome-user-docs*. When
I press the lock screen button, I get the log in screen. The reason may be:
1. I am using an older version of Ubuntu-gnome (the latest LTS version)
