Arduino IDE Choose Bad Com Port

Hi to all.

I have Arduino MKR WAN 1300 on com port 8.
When I compile and upload, Arduino IDE (1.8.9) says:

Sketch uses 11164 bytes (4%) of program storage space. Maximum is 262144 bytes.
Forcing reset using 1200bps open/close on port COM8
PORTS {COM8, } / {} => {}
PORTS {} / {COM11, } => {COM11, }

I dont' have COM11. I have only COM8.

Upload is ok (i try with a simple code that blink internale led) on arduino, but the log ends with:

Couldn't find a Board on the selected port. Check that you have the correct port selected. If it is correct, try pressing the board's reset button after initiating the upload.

More info here:

How can I remove this annoying message?



I dont' have COM11. I have only COM8.

COM8 is the COM port enumerated to your board while the sketch is running. When you upload to a native USB board like the MKR WAN 1300, the board it reset and the bootloader is activated. Windows enumerates a different COM port for the bootloader, in this case COM11. So in face you do have COM11, but only temporarily while the bootloader is running. You can see this if you run Windows Device Manager during the upload. So this is normal and expected.

What's not is the spurious upload error. I suspect you're encountering this bug:

Does the problem go away if you close all Arduino IDE windows and then restart the Arduino IDE?

That bug has been fixed in the hourly build of the Arduino IDE if you want to give it a try:

Thanks for your kind and exhaustive response.
I don't have multiple COM port in "tools -> port", but hourly build resolve my problem :)))

Thank you Pert!


You’re welcome. I’m glad to hear it’s working now. Enjoy!