It can be that your Fly6 entered Safe Mode or Incident Protection was triggered.
If the battery has depleted to a level 5% or below, the camera and audio functions will shut down. Fly6 will enter safe mode leaving the flashing lights functioning. This can last up to a further 1.5 hours. Simply give your unit a full charge and it will function normally.
A G-sensor is installed in the device and if it has established that the unit has been tilted past 60 degrees (or 30 degrees from the ground), it will activate the Incident Protection Mode. Dependent on the battery status, the device will record and turn off after 1 hour.
When incident protection was triggered by accident, just grab the unit, turn it off and back on. It will continue to function normally.