I was pretty excited when Motorola announced the release of Android 5.0 Lollipop for the AT&T variant of the Moto X. "I could finally start using all of the new features found in Lollipop!" But more specifically, I could finally set Smart Lock to keep my device unlocked when I'm home.
My excitement quickly turned to disappointment as I went to enable the feature. I opened the Settings app, tapped on Security and found the Smart Lock option to be missing.
I rebooted my device, thinking it would fix it. Which was a lie. Then I frantically tapped through the Settings app, hoping the feature had just been moved. It hadn't.
After some time I took to Google to find an answer. My search lead me to this forum post where another Moto X user was suffering the same issue I was. Feeling reassured by the fact I wasn't alone, I read on.
As it turns out, for reasons unknown, some users need to enable Smart Lock before you can, well, enable Smart Lock. This is done by launching Settings, selecting Security followed by Trust Agents at the bottom of the list. Slide the switch next to Smart Lock (Google) to On, and back out of the screen.
Once that's done, you can find the proper Smart Lock feature at the top of the Security section of your device.