Uploading to new Uno

It was not the same. There are many possible causes of a compilation or upload error. The error messages can be somewhat cryptic and there is a lot of output, some of which you will get even during a successful operation, so it can be difficult to determine which part to focus on. In this case, it was here:


I recommend that you do this:

  1. Select File > Preferences from the Arduino IDE menus.
  2. Uncheck the box next to "Show verbose output during: [x]Compilation".
  3. Click the OK button.

The verbose compilation output is very verbose and most of the output is not at all useful to the normal user on a daily basis. It is more useful for troubleshooting problems with the Arduino IDE itself, rather than problems with your own code or board. You might enable it temporarily as needed if you are having a strange compilation failure or if you get curious to learn more about what the Arduino IDE does during a sketch compilation.

I recommend always leaving the verbose upload output enabled because there isn't so much of it and even when the upload is working fine it provides some nice visual feedback about the progress of the upload.