Hi,
I give you the conclusion of my unexpected fail.

That was effectively /etc/sudoers which was corrupted and RescueOs was perfect to fix the problem. Thanks again freemangordon.



But, Flasher3.5 does not work with Windows10 nor WindowsXp into a virtual machin. Luckily, 0xFFFF works very well under a virtual machin where fedora34_x86_64 is installed.

Thank you, folks.