DJI MSDK v5.7 Take off Fails

Question

I have this code:

FlightControllerKey.KeyStartTakeoff.create().action({
    Log.d("takeoff","TakeOff Success")
}, { e: IDJIError ->
    Log.d( "takeoff","DJI Takeoff error: " + e.description())
})

This does not work, and the error message is null. The full error is: ErrorImp{errorType='CORE', errorCode='SYSTEM_ERROR', innerCode='', description='null', hint='error code = -7'}

I also tried with this:

KeyManager.getInstance().performAction(KeyTools.createKey(FlightControllerKey.KeyStartTakeoff),


        object: CommonCallbacks.CompletionCallbackWithParam<EmptyMsg> {
            override fun onSuccess(
                    nil: EmptyMsg
            ) {
                Log.i(
                        "Drone Action",
                        "Taking off"
                )
            }

            override fun onFailure(
                    error: IDJIError
            ) {
                Log.i(
                        "Drone Action",
                        "Takeoff failed $error"
                )
            }
        }

        )

I get the same: Takeoff failed ErrorImp{errorType='CORE', errorCode='SYSTEM_ERROR', innerCode='', description='null', hint='error code = -7'

I also tried:

FlightControllerKey.KeyStartTakeoff.create().action({
    Log.d("Monsoon Command Execution : ", "takeoff success!")

}, { e: IDJIError ->

    val d = e.description()

   Log.d("Drone Command Execution : ", "takeoff error! $d")

})

I get takeoff error ! null

I am using MSDK V 5.7. This happens ever after I arm the drone by pulling back the joysticks and to the center. Drone is connected to the simulator in DJI assistant enterprize

Why do I get this kind of errors? Please, I need a quick solution. Thank you.