What does the message "unfortunately has stopped error" on Android mean?

[AC Question]

what causes the message unfortunately has stopped error on a lg g4 stylo phone when my phone is under a certain percentage on battery life?

 

[ManiacJoe]

The error is just a polite message from the operating system telling you that the named app has crashed.
Normally it is due to a programming error, or a hardware error, or maybe a lack of power. Either way, you the user will probably not know why it happened.
If there is a log of the crash, there may be enough info in the log that a programmer or other knowledgeable person might find helpful.

If the problem is always happening at the time of low power (like 3% available), then you probably just need to stay away from that situation since the power level is just an estimate and computer-type devices do not like low-power states.