I have succeeded in restoring my firmware using the u2d2.
I run into the same issue when I using the lerobot/examples/7_get_started_with_real_robot.md at main · huggingface/lerobot · GitHub.
It is better to change the instruction otherwise there will be a lot complaints.
Now have to buy a U2D2 for firmware restoring. 
And will cost me additional $50.
Solved this by using linux version DynamixelWizard2