Hi, This is my first trial. I selected Tools > port "COM4 Arduino(Arduino/Genuino Uno)" which is my only available port. Where is this "\.\COM4" missing file ? Thanks for help Jean

avrdude: ser_open(): can't open device "\\.\COM4": Le fichier est introuvable

sterretje October 30, 2017, 5:50am 2

No idea about the problem. What does device manager say when you connect and disconnect the Arduino? Is it indeed COM4 that shows and disappears?

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