Weird error on lockscreen
Hello guys. I stopped using my iPhone and when I wanted to use it again a few hours later I found out that the screen was turned on and was displaying this weird error. The phone was warm and the battery decreased 24% (it had 82% last time), so I guess the phone had been turned on for a while. What does this error mean ? and how can I fix it?
iPhone 6, iOS 8.3