PW3 5.16.2.1.1 — WinterBreak 2.0 jb.sh runs, but sh_integration/KPM appear nonfunctional

[scheatham-pastor]

Device: Kindle Paperwhite 3 (7th Generation / PW3)
Firmware: 5.16.2.1.1
Jailbreak: WinterBreak v2.0.0
Goal: Install KOReader

I attempted to jailbreak a PW3 running 5.16.2.1.1 using WinterBreak v2.0.0.

WinterBreak successfully triggered and jb.sh visibly executed on the Kindle. During execution I saw output including:

• Powered by jb.sh
• Copying the jailbreak updater keystore
• Setting up sh_integration
• Removing mkk

Afterward, a JAILBROKEN document appeared in the Kindle library.

On USB storage, /libkh/bin/fbink is present, so at least part of the installation appears to have completed.

However, the post-jailbreak environment does not appear to be functioning correctly.

sh_integration behavior

I placed a test .sh file in /documents. The Kindle indexed it and displayed it in the library, but tapping it opened the shell script as a text document rather than executing it.

KPM behavior

I attempted:

;kpm

and later:

;kpm install koreader

KPM did not successfully launch/install KOReader. Instead, the Kindle generated KPPMainAppV2... and cvm... crash/debug artifacts. One of the cvm core dumps was approximately 61 MB.

Searching the user-accessible USB storage for kpm did not return anything, although I realize KPM components may not necessarily reside in ser-isible storage.

The Kindle itself continues to boot and operate normally and remains on firmware 5.16.2.1.1.

Additional troubleshooting performed

I subsequently tried preparing WinterBreak2 (jb.sh, patchedUks.sqsh, and winterbreak2 at /mnt/us), but the PW3 Experimental Browser cannot access the Internet even though Wi-Fi connects, so I did not successfully execute the WinterBreak2 browser exploit.

I also downloaded Update_hotfix_universal.bin, but Update Your Kindle remained grayed out, so I did not attempt to force installation. I subsequently removed that .bin.

I have stopped making further changes and currently have the Kindle in Airplane Mode.

Questions

1. Does this indicate that jb.sh completed the initial jailbreak but failed during post-installation?
2. Is there a supported way to rerun/repair sh_integration and KPM without repeating the jailbreak?
3. Should I rerun jb.sh, use another installation method, or remove any remnants from the original WinterBreak installation first?
4. Once repaired, is ;kpm install koreader still the recommended KOReader installation method for PW3/5.16.2.1.1?

I can provide directory listings, crash/debug files, photos of the jb.sh output, or other diagnostics if useful.

[scheatham-pastor]

Just following up on this issue. The PW3 remains on 5.16.2.1.1 and has been kept in Airplane Mode since I filed the report, so its state should be essentially unchanged. I'm happy to provide any additional logs/files or run specific diagnostics if that would help. Thanks!