Crashed Log Analysis

We faced with a crash of our quadcopter which uses a Cube (ArduCopter 3.6.9). These are the details:

  1. First flight was conducted for about 5 minutes, which went fine.
  2. Second flight was of 6 minutes. There was a communication failsafe issue, after which the vehicle showed erratic behaviour ultimately leading to a crash.
    The log is available here.
    AUTO Analysis showed this:

    We don’t understand some of the information given by the AUTO Analyser.
    Can anyone help us with this, so that we can identify the issue?

Hi Annie
it seems that your motor 3 (or ESC) failed in air when your copter at 40m altitude.