Troubleshooting U007 error when trying to install MKK

Carbon46 · 04-13-2026, 10:41 AM

I have followed the jailbreaking tutorial for my kindle 4 NT on the kindle modding wiki, all the wa through and when I try to open KUAL, I get the error "Mobileread Kindlet Kit is not installed". I have then tried to install MKK, but everytime I try to install, using the K4 ALL bin, I get a U007 code error when tring to update. I've tried starting the jailbreak from scratch but still had the same issue. My kindle is registered and I've been doing this with airplane mode on.
Any help will be greatly appreciated!

dcarvil · 04-13-2026, 11:52 AM

Quote:

Originally Posted by Carbon46

I have followed the jailbreaking tutorial for my kindle 4 NT on the kindle modding wiki, all the wa through and when I try to open KUAL, I get the error "Mobileread Kindlet Kit is not installed". I have then tried to install MKK, but everytime I try to install, using the K4 ALL bin, I get a U007 code error when tring to update. I've tried starting the jailbreak from scratch but still had the same issue. My kindle is registered and I've been doing this with airplane mode on.
Any help will be greatly appreciated!

kindle-mkk-20141129-r18833 worked for me.

ItsHarper · 04-21-2026, 01:38 AM

I have this issue, with the version of MKK mentioned by dcarvil, with Kindle software version 4.1.4. Which version of the software is your Kindle running?

ItsHarper · 04-21-2026, 02:46 AM

I need to go to bed, but someone said that installing the specific version of the JB linked here fixed this issue: https://www.mobileread.com/forums/sh...d.php?t=225030

dcarvil · 04-21-2026, 11:51 AM

Quote:

Originally Posted by ItsHarper

I have this issue, with the version of MKK mentioned by dcarvil, with Kindle software version 4.1.4. Which version of the software is your Kindle running?

Not sure who you are asking, but I am on 4.1.4.

lunarblaze · 05-08-2026, 06:00 AM

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

04-13-2026, 10:41 AM	#1
Carbon46 Junior Member Posts: 1 Karma: 10 Join Date: Apr 2026 Device: Kindle 4	U007 error when trying to install MKK I have followed the jailbreaking tutorial for my kindle 4 NT on the kindle modding wiki, all the wa through and when I try to open KUAL, I get the error "Mobileread Kindlet Kit is not installed". I have then tried to install MKK, but everytime I try to install, using the K4 ALL bin, I get a U007 code error when tring to update. I've tried starting the jailbreak from scratch but still had the same issue. My kindle is registered and I've been doing this with airplane mode on. Any help will be greatly appreciated!

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04-21-2026, 01:38 AM	#3
ItsHarper Junior Member Posts: 3 Karma: 10 Join Date: Apr 2026 Device: Kindle 4 (NT)	I have this issue, with the version of MKK mentioned by dcarvil, with Kindle software version 4.1.4. Which version of the software is your Kindle running?

04-21-2026, 02:46 AM	#4
ItsHarper Junior Member Posts: 3 Karma: 10 Join Date: Apr 2026 Device: Kindle 4 (NT)	I need to go to bed, but someone said that installing the specific version of the JB linked here fixed this issue: https://www.mobileread.com/forums/sh...d.php?t=225030

05-08-2026, 06:00 AM	#6
lunarblaze Junior Member Posts: 2 Karma: 10 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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