You can try a reboot...I can't even find this option, I would be interested in knowing where it's located ?Even though I have "show custom message" checked and a custom message entered in, my custom message is not showing on the lockscreen. How do I get it to show?
It's working after a reboot.
The option is under the "Location and Security" menu in settings. You should see a checkbox to "show custom message." And underneath that an option to type in what you'd like your custom message to be.