There seems to be some IDE versions that check if you already included it so they don’t include it twice, but version 1.8.5 didn’t seem to do that. Maybe I can add some options in the ...

Arduino IDE 1.6.9 Now Available To ... – the problem with FTDI serial ports on Windows introduced with IDE 1.6.8 has been fixed ... be sure to check the whole changelog for a complete list of ...