Not able to fly in jMAVSIM (Not able to disarm)

[JLTang]

Hello all,
Im using the qgroundcontrol (version 2.9) and update the firmware, then disconnect, then open up jMAVSim. Up to this point, from the terminal I can see the following:

Init MAVLink
MSG: [inav] GPS timeout
MSG: [inav] GPS signal found

After that, Im trying to turn off the safety switch to enable the motor on my drone (IRIS 3DR), but no respond. I also tried to disarm it from my RC, but also no respond.

Im using Ubuntu 14.04
The lines I used to run jMAVSIM were:

1. java -cp lib/_:out/production/jmavsim.jar me.drton.jmavsim.Simulator
   OR
2. java -Djava.ext.dirs= -cp lib/_:out/production/jmavsim.jar me.drton.jmavsim.Simulator -serial /dev/ttyACM0 921600 -qgc

Any help will be appreciated! Thanks!