Date and time panel is greyed out, how do I restore it?

Date and time is showing in the login screen (unity-greeter) but not when I login to my session.

When I go to date and time settings the panel is all grey :

Any idea how to recover from this ?

2 Answers

This looks like a bug.

Try to reinstall gnome-control-center using the following commands from terminal:

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install --reinstall gnome-control-center

I had to reinstall libmessaging-menu0 under Ubuntu 18.04 using the following commands:

sudo apt-get install --reinstall libmessaging-menu0

I found out the above shared library was missing by running the indicator-datetime-service manually as

/usr/lib/x86_64-linux-gnu/indicator-datetime/indicator-datetime-service