KFXKeyExtractor28 does not generate keys

[sclassing]

Question / bug report

When I run KFXKeyExtractor28.exe no key files are output.

I put the KFXKeyExtractor28.exe in C:\Users\micro\AppData\Local\Amazon\Kindle\application
I run: KFXKeyExtractor28.exe "C:\Users\micro\OneDrive\Documents\My Kindle Content" kindle4pc.txt kindle4pc.k4i

Which version of Calibre are you running?

9.8.0

Which version of the DeDRM plugin are you running?

v10.0.28

If applicable, which version of the Kindle software are you running?

2.9.1 (7106)

Log output

C:\Users\micro\AppData\Local\Amazon\Kindle\application>KFXKeyExtractor28.exe "C:\Users\micro\OneDrive\Documents\My Kindle Content" kindle4pc.txt kindle4pc.k4i
Scanning C:\Users\micro\OneDrive\Documents\My Kindle Content for book folders
adding search dir C:\Users\micro\AppData\Local\Amazon\Kindle\application
Kindle Directory: C:\Users\micro\AppData\Local\Amazon\Kindle\application\Kindle.exe
Found sought after function
Found sought after function

[ElleKayEm]

The number at the end indicates the highest version it works for. For 2.9.1, use KFXArchiver291.exe. See discussion over at Satsuoni's repo:
Satsuoni#55