Possible Causes:
Drone power distribution board overheated
Overheated battery or bad battery
Troubleshooting Steps:
Put a known good battery into drone and see if error goes away
See if a update is available for the drone or battery, if so update
Replace Power Distribution Board on drone
Replace Spray module if replacing Power Distribution Board does not work
Prevention:
This issue can sometimes be prevented by good heat management of the drone and batteries. See our article here on Tips On How To Keep Batteries and Drones Cool To Prevent Forced landings