Error adding geofences in Android (status code 1000)
You get GEOFENCE_NOT_AVAILABLE (code '1000') when user disagrees to "Use Google' location services" in Settings->Location->Mode: 
To fix it:
- go to Settings->Location->Mode
- set "Device only (Use GPS to determine your location)"
- set any other option to get the popup (e.g. "High accuracy (Use GPS, Wi-Fi and mobile networks to determine location")
- dialog ""Use Google' location services" is shown
- choose "Agree"
Posting this answer since the settings in Android have changed a lot. I had this error twice when I was running a Nexus 5X emulator running API 28. I managed to solve it both times by doing the following:
- Turn off your application you are developing (don't let it be in the background)
- Go to Settings -> Security & Location -> Location -> Advanced -> Google Location Accuracy. Turn 'Improve Location Accuracy' off.
- Turn on 'Improve Location Accuracy'
Turn on your application again and adding geofences worked for me after I took these steps.
EDIT: I ran into this issue again a few months later, sometimes the emulator is stubborn and does not actually turn on location accuracy correctly to allow Google's Geofence API to recognise it is turned on. I had turn 'Improve Location Accuracy' on and off at least 10 times before location accuracy worked.
Is a little later, but just now I had this issue. My guess is:
you are using any kind of fake GPS on your tests (Lockito, emulator, etc)?
I took some hours until I found out that the fake locations seems to disable the Geofence support! You cannot register or trigger a Geofence if you are not really in the location.
If you turn off the fake GPS,the Geofence support become enabled again.