Sigh, I have a feeling that letting users see the output messages complicates things… They are just the output from running the avrdude command. If you want to take a close-up look at the messages, you can bypass the GUI and run avrdude in command line directly. For exmaple:
avrdude -c usbasp -p m644p -U flash:w:firmware2.0.6.hex
is what it’s really running.