Hacks Issue with Kindlet: "This title is not signed by a registered developer"

mrfakename · 03-16-2025, 05:35 PM

Hi everyone,

I’m a complete beginner to Kindlet development but I’m trying to make a basic Kindlet for my Kindle 3W. I successfully jailbroke my Kindle and installed MKK, KUAL, and Launchpad. I used Launchpad to copy my developer keystore over.

I was able to successfully run KUAL and KIF (an IF Kindlet). However, when I try running the Kindlet I compiled, I get:

“This title is not signed by a registered developer”

I switched to using KUAL’s keystore (https://bitbucket.org/ixtab/kindlela...loper.keystore), but I’m still getting the same issue, even though I can launch KUAL.

Would anyone be able to provide suggestions on how to resolve this issue? Any assistance would be greatly appreciated.

Edit: I noticed that my error message says "This title is not signed by a registered developer," however when researching similar errors, the message often says "This item is not signed by a registered developer." Not sure if the difference (title vs. item) has any significance.

KindleHaxxor · 05-02-2025, 11:42 PM

Me too, I'm also getting this error. I tried to modify the policies, but it still shows it.

KindleHaxxor · 05-09-2025, 12:31 AM

Actually I found the issue. Turns out, their keystore had expired. They did provide another keystore, but it took a while to find it. Here: https://www.mobileread.com/forums/sh...postcount=1295

lSpencer · 08-12-2025, 03:56 PM

I noticed this error and the link to the update for keystore worked for KUAL but not for kif. Did you get any joy on kif?

03-16-2025, 05:35 PM	#1
mrfakename Developer Posts: 30 Karma: 15056 Join Date: Mar 2023 Device: Kindle Paperwhite 3W	Issue with Kindlet: "This title is not signed by a registered developer" Hi everyone, I’m a complete beginner to Kindlet development but I’m trying to make a basic Kindlet for my Kindle 3W. I successfully jailbroke my Kindle and installed MKK, KUAL, and Launchpad. I used Launchpad to copy my developer keystore over. I was able to successfully run KUAL and KIF (an IF Kindlet). However, when I try running the Kindlet I compiled, I get: “This title is not signed by a registered developer” I switched to using KUAL’s keystore (https://bitbucket.org/ixtab/kindlela...loper.keystore), but I’m still getting the same issue, even though I can launch KUAL. Would anyone be able to provide suggestions on how to resolve this issue? Any assistance would be greatly appreciated. Edit: I noticed that my error message says "This title is not signed by a registered developer," however when researching similar errors, the message often says "This item is not signed by a registered developer." Not sure if the difference (title vs. item) has any significance. Last edited by mrfakename; 03-16-2025 at 06:03 PM.

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05-02-2025, 11:42 PM	#2
KindleHaxxor Junior Member Posts: 4 Karma: 10 Join Date: May 2025 Device: Kindle Keyboard 3G	Me too, I'm also getting this error. I tried to modify the policies, but it still shows it.

05-09-2025, 12:31 AM	#3
KindleHaxxor Junior Member Posts: 4 Karma: 10 Join Date: May 2025 Device: Kindle Keyboard 3G	Actually I found the issue. Turns out, their keystore had expired. They did provide another keystore, but it took a while to find it. Here: https://www.mobileread.com/forums/sh...postcount=1295

08-12-2025, 03:56 PM	#4
lSpencer Junior Member Posts: 4 Karma: 10 Join Date: Mar 2011 Device: kindle3w	I noticed this error and the link to the update for keystore worked for KUAL but not for kif. Did you get any joy on kif?

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