Thread: Troubleshooting U007 error when trying to install MKK
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Old 05-08-2026, 06:00 AM   #6
lunarblaze
Junior Member
lunarblaze began at the beginning.
 
Posts: 2
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Join Date: May 2026
Device: Kindle gen4 (black not touch), Kobo Forma
Hello!

Thank you ItsHarper, you're right it works!
I had the same issue and it fixed it for me. I hadn't realised that the jailbreak linked on the MobileRead forum thread is not the same as the wiki one.

My situation was similar to Carbon46's:
- Registered K4, on airplane mode.
- Firmware applied manually with airplane mode "on" from 4.1.1 to 4.1.4.
- I followed the Kindle modding wiki instructions to jailbreak, and got the "you are jailbroken" file confirmation.
- After that I have to admit I didn't really understand which branch I had to follow on the wiki, but in any case the KUAL-KDK-1.0.azw2 said that "mobileread kindlet kit is not installed" when I opened it. I tried to install mkk but stumbled upon U007 errors.

Solution:
- I didn't need to reset anything.
- From where I was I scrupulously followed the guide on this Reddit post: https://www.reddit.com/r/kindle/comm...mment/mcw6m8t/ , which links to files from the aforementioned MobileRead thread.

I can now open the KUAL document and launch Koreader
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