MacBook and Mega 2560: Error "USB Port already in use"

Hi.

I just tried to upload the “Blink” sketch to my new (and first) Arduino. Whatever I tried, I got the message that the USB Port is already in use or the message “avrdude: usbdev_open(): did not find any USB device “usb””.

I already tried:

  • another USB Cable
  • connecting it directly to the Mac
  • disabling / disconnecting everything I do not absolutely need for Arduino
  • a second profile on my Mac
  • the solution of Adam.S ( installing new ftdi and vcp drivers)

What I have:

  • MacBook 2008, OS X 10.9.4
  • Arduino MEGA 2560, Power LED “on”, LED L blinking, nothing connected to it (Except USB Cable)
  • ARDUINO 1.0.5, set to “Board: Mega 2560…” and “Serial Port: /dev/tty.usbmodem621”

Any suggestions?

Thanks in advance!!!