Kindle Book Cover Bug Strikes Again?

[AtavachronWill]

I'm running Calibre 9.15 and just synced my new Kindle Aluminum (latest firmware): 90% of the covers are missing. I tried the old plug it back in trick, but it didn't help.

I've been through this numerous times before and suspect it is simply a matter of time before Calibre is updated to fix it. . .but, I am wondering if anyone else is having the problem with the newest Kindles?

[JSWolf]

Originally Posted by AtavachronWill

I'm running Calibre 9.15 and just synced my new Kindle Aluminum (latest firmware): 90% of the covers are missing. I tried the old plug it back in trick, but it didn't help.

I've been through this numerous times before and suspect it is simply a matter of time before Calibre is updated to fix it. . .but, I am wondering if anyone else is having the problem with the newest Kindles?

The Kindles with MTP prevent access to the directory calibre needs to put the cover in. There is no way around this unless a jailbreak can give calibre access to that directory. And for now, there's no ailbreak for the new 2026 Kindles.

What firmware are you running?

[AtavachronWill]

My 2024 Kindle Paperwhite has no trouble with covers--never has.

[AtavachronWill]

Oops. Firmware is 5.19.6.

[kovidgoyal]

I dont currently have access to this hardware so the fix if possible at all will have ot come from someone who does.

[AtavachronWill]

I have the hardware and a 2024 MTP Paperwhite for comparison. I’m happy to run diagnostics, inspect files, test debug builds, or provide whatever information would help.

[kovidgoyal]

This requires investigation cant really do that by proxy. But as basic sanity check restart calibre in debug mode by right clicking the preferences button and then plug in your device and send a book over and the quit calibre and post the debug log

[JSWolf]

A debug log won't help. It can't be done because Kindles with MTP restrict access to the directory needed to put the covers in.

[AtavachronWill]

Originally Posted by JSWolf

A debug log won't help. It can't be done because Kindles with MTP restrict access to the directory needed to put the covers in.

No disrespect, but I'm not sure what you are talking about. I've been using a 2024 Paperwhite for two years and all my books have covers.

[AtavachronWill]

Originally Posted by kovidgoyal

This requires investigation cant really do that by proxy. But as basic sanity check restart calibre in debug mode by right clicking the preferences button and then plug in your device and send a book over and the quit calibre and post the debug log

I omitted the middle of the debug log because it contains a listing of the books on the device. Here are the environment/device details and the section covering the test transfer:


calibre Debug log
calibre 9.15 embedded-python: True
macOS-27.0-arm64-arm-64bit-Mach-O Darwin ('64bit', 'Mach-O')
('Darwin', '27.0.0', 'Darwin Kernel Version 27.0.0: Tue Aug 11 21:05:27 PDT 2026; root:xnu-13432.1.9~1/RELEASE_ARM64_T8103')
Python 3.14.7
OSX: ('27.0', ('', '', ''), 'arm64')
EXE path: /Applications/calibre.app/Contents/MacOS/calibre-debug

Successfully initialized third party plugins:
KFX Output (2, 21, 0)
KFX Input (2, 34, 2)
KFX metadata reader (from KFX Input) (2, 34, 2)
Set KFX metadata (from KFX Output) (2, 21, 0)

Device 0 (VID=1949 and PID=9981) is a Amazon Kindle Scribe 32GB.

Job: 3 Upload one book to the device: The Satanic Verses: A Novel started
Device using plugboard kfx MTP_DEVICE None

Setting metadata in: The Satanic Verses: A Novel
KFX metadata writer activated
Processing container

A list of 531 approximate pages is already present with auto pages desired
Features: CanonicalFormat-1, kfxgen.pidMapWithOffset-1, kfxgen.textBlock-1, reflow-section-size-5, reflow-style-1

Metadata: ASIN=85C4MPSNQ1N6D2S8J8A14AV17AA5CIXN, asset_id=CR!869464F1HUWJYX3SAWI3I1HOHIQ7, author="Rushdie, Salman", book_id=j6YCB786RwS98fUujDhK4w0, cde_content_type=EBOK, content_id=85C4MPSNQ1N6D2S8J8A14AV17AA5CIXN, cover_image=898x1388, creator_version=3.89.0, file_creator=KPR, is_sample=False, issue_date=2011-02-22, kfxgen=kfxlib-20250220, language=en, max_id=834, min_kindle_version=5.6.5, nested_span=enabled, override_kindle_font=False, pages=531, publisher="Random House Publishing Group", reading_orders=1, selection=enabled, title="The Satanic Verses: A Novel"

Failed to upload cover thumbnail to system/thumbnails with error: Failed to create folder named system in ('Internal Storage',) with error: 2:PTP Layer error 2002: LIBMTP_Create_Folder: Could not send object info.
2:Error 2002: PTP General Error

Failed to generate APNX
Traceback (most recent call last):
File "calibre/devices/mtp/driver.py", line 731, in upload_apnx
File "calibre/devices/kindle/apnx.py", line 44, in write_apnx
File "calibre/devices/kindle/apnx.py", line 79, in get_apnx_meta
Exception: Not a valid MOBI file.

MTP: upload_books() called
MTP: upload_apnx() called
MTP: Uploading APNX file for ('documents', 'Satanic Verses_ A Novel, The - Rushdie, Salman.kfx')
MTP: upload_apnx() ended
MTP: upload_books() ended

DeviceJob: 3 Upload one book to the device: The Satanic Verses: A Novel done, calling callback
MTP: add_books_to_metadata() called
MTP: add_books_to_metadata() ended
DeviceJob: 3 Upload one book to the device: The Satanic Verses: A Novel callback returned

Job: 4 Send metadata to device started
MTP: sync_booklists() called
Job: 3 Upload one book to the device: The Satanic Verses: A Novel finished
MTP: sync_booklists() ended
DeviceJob: 4 Send metadata to device done, calling callback
DeviceJob: 4 Send metadata to device callback returned
Job: 4 Send metadata to device finished

[kovidgoyal]

There's your issue creating the system folder which is what is needed for the cover workaround is failing, look at the lines

Failed to upload cover thumbnail to system/thumbnails with error: Failed to create folder named system in ('Internal Storage',) with error: 2:PTP Layer error 2002: LIBMTP_Create_Folder: Could not send object info.
2:Error 2002: PTP General Error

[AtavachronWill]

Originally Posted by kovidgoyal

There's your issue creating the system folder which is what is needed for the cover workaround is failing, look at the lines

Failed to upload cover thumbnail to system/thumbnails with error: Failed to create folder named system in ('Internal Storage',) with error: 2:PTP Layer error 2002: LIBMTP_Create_Folder: Could not send object info.
2:Error 2002: PTP General Error

I did some further testing. I found that the books whose covers display are KFX files with cde_content_type=PDOC, while those with missing covers are EBOK.

I removed an affected EBOK (Blackfish City), deleted its existing KFX in Calibre, reconverted the EPUB to KFX with “Create book (EBOK) instead of personal document (PDOC)” unchecked, and resent it.

The newly generated PDOC immediately displayed its cover correctly, despite Calibre still being unable to write to system/thumbnails. The Kindle menu also changed from “Remove download” for the EBOK to “Permanently delete” for the PDOC.

So it appears PDOC KFX can use the embedded cover on this device, while EBOK KFX depends on the inaccessible system/thumbnails mechanism.

[kovidgoyal]

You can have it with MOBI as well, see the FAQ: https://manual.calibre-ebook.com/faq...-the-book-list

[AtavachronWill]

One further useful result: I confirmed that I do not need to reconvert existing KFX files.

In KFX Output, I left Create book (EBOK) instead of personal document (PDOC) unchecked, and in the KFX Output plugin settings I enabled Update all KFX metadata.

I then removed another affected book from the Kindle and resent its existing KFX file from Calibre, without reconverting it.

On send, the KFX metadata writer changed the file from EBOK to PDOC. The cover then displayed correctly on the new Kindle, and the menu changed from Remove download to Permanently delete.

So existing KFX files can apparently be fixed simply by rewriting the metadata from EBOK to PDOC during Send to device. No reconversion is required.

[DNSB]

Originally Posted by AtavachronWill

No disrespect, but I'm not sure what you are talking about. I've been using a 2024 Paperwhite for two years and all my books have covers.

Compared to the USBMS Kindles, MTP Kindles do not expose some of the directories which includes the one used by the calibre Kindle cover fix. Sending a PDOC instead of a EBOK works around that issue.