This morning lefrissült phone on Android 6.0. Since then, more than two minutes to turn on. Very slowly, the two do not go sim usual. I can not make phone calls on the second sim card. The battery is also very exhausted. Applications stop error. How do I return to Android 5.1? Where can I download it? I ask for help because the phone is so useless.
(So far it worked wonderfully!)Thank,
Peter