@ cidiemme,
I second that Thanks. Cheers.
paoloh1950:
Same problem of tty ports disappeared in El Capitan.
Any port showed isn't good.
I have an Arduino Uno Rev.3 board equipped with ATMEGA 16U2.
Arduino IDE is 1.6.5
I think that installing CH340 drivers is a nonsense in my case.
Thanks to everybody can help me.
I have Uno Rev 3 working fine on the latest version of the IDE. I think I downloaded and installed it again and all was good after that.
Good Luck