HI,
I am trying to load a sketch but I get the error message mentioned in the title.
I checked the selected board in the "Tools menu" (Arduino Uno, which is right) but I guess it is a problem of port. The only serial port I can choose is "/dev/cu.Bluetooth-Incoming-Port " while the board is connected with a USB cable.
I guess I need the good drivers but I know neither which ones nor where to find them.
I use a Mac,
OS X 10.11.6,
Arduino 1.8.12
In the Tools menu, I also see
Programmer: "AVRISP mkll"
Thanks for helping and sorry for my lack of experience.
Sounds like you may indeed need to install FTDI or CH340 drivers depending on board. The port should come up as something like /dev/tty.usbserial-xxxxx
FTDI drivers:
https://www.ftdichip.com/Drivers/VCP.htm
CH340 drivers:
Check the supply voltage, and how much it drops while Writing then Verifying the upload to it.
Some CP2102 modules fail to deliver enough power resulting in this, and other similar intermittent errors.
eg "out of sync", "programmer is not responding"
Sometimes the Write will succeed, but the Read that follows will fail. All caused by lack of power to the board.