Port not open

[indavidjool]

When I attempt to run the install as per the reference manual (python s2a_fm.py /dev/ttyACM0) the RX LED on my Arduino Mega blinks rapidly but then I get the following exception: serial.serialutil.SerialException: Attempting to use a port that is not open.
As far as I can tell I did not skip an installation step. Attached is the terminal output for the complete messages.

[indavidjool]

My apologies. I did skip an installation step:
Load Standard Firmata into the Arduino from the examples directory of the Firmata library included
with the Arduino IDE
Perhaps the reference manual requires a few more words explaining the steps to take to do this.

[MrYsLab]

I am glad that you figured it out and it is working for you. I will keep that in mind if I update the documentation.