I was showing the location option to someone and found it doesn;t work on my phone now. It used to work. I have find my iPhone enabled on the phone through iCloud, and location service is enable for find my iPhone. On iCloud.com it can see the phone, I can play a sound on it, but wont show the location. It says "Online. No location available" I thought the phone periodically sent the location at all times, so even if off then it would still have th last known location. Any ideas n why it wont show up, or what setting has been missed? Also how do you enable the activation lock that prevent other people turning the find my iPhone off?