Accessory Not Supported
IPad is locked; can’t force it to reboot, can’t lose the Message screen. Nothing is plugged into it. Help.
iPad Air 2
Question marked as
See >>> If you see an ‘Accessory may not be supported’ alert - Apple Support
If you are using a Smart (folio) keyboard, the alert is typical of a faulty folio keyboard. The electrical connections that pass through the flexible fabric hinges typically fracture - this usually resulting in errors and/or the on-screen notification that you see.
If your iPad is unresponsive while connected to a keyboard, disconnect the keyboard.