Ceiling Sensor Light Blinking/Off

 
Any time you see the ceiling sensor light blink 10x fast, it means the ceiling sensor is too far from a gateway, but it is powered and picking up the beacons.
 
If the LED is off, the power is the problem.
 
If it doesn't blink when a beacon is nearby, it's not picking up the beacon. It could be a beacon, ceiling sensor, or lighting problem.