Bootmode.
Or keep trying to get it to work with lower baudrates.
No need for plan B!
Mr Nyet, I would like to thank you for you help! I persisted on trying to get the lower baud rates, and finally succeeded. The trick was to connect, and only then drop the baud rate again before flashing.
It flashed the file in about 5 minutes.
How can I repay you, sir?
