[Kindle 4 black] Can't install Mkk and Kual

Hi all,
i just purchased from a friends this Kindle 4 black, used but looks brand new.
I didn't set an amazon account and not registered the device with my amazon account, i want to jailbreak it and install Duokan.
The first thing I do, is jailbreak it, pretty easy, after the procedure I have a new book that say tha i'm jailbroken.
After that I want to install Kual and Mkk, so I install Mkk as an update using this file:
after a reboot I put:
inside my documents, but when i select it it says:
tried to reinstall Mkk, but Kual give me the same error.
What can I do?
If you need further information don't hesitate