Failed to upload cover thumbnail (Kindle Paperwhite 2024)

[lasyan3]

Hi there,
I have a Kindle Paperwhite 2024 on which I transfert some azw3 files and I have an issue with the covers not being updated (yeah I know, very original ^^).

From my investigation, I can see the folder "amazon-cover-bug" is not filled.
I ran Calibre in debug mode and I found this error:

Failed to upload cover thumbnail to system/thumbnails with error: Failed to create the folder: thumbnails in ('Internal Storage', 'system') with error: C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:619:Failed to create folder:[hr=0x80004005 wCode=0] Erreur non spécifiée

This is really strange because the folder thumbnails exists in system. Why does Calibre try to create it? It's as if it doesn't see it (permission issue maybe?)

I tried rebooting both the computer and the device but no luck...
I know this error is linked because when I manually add a jpg file in the system/thumbnails folder, with the right guid, the cover show in the device.
Any clue?

PS : have a good New Year's Eve!

[DNSB]

The 2024 Kindle devices use MTP and do not expose the system directory over a USB connection. This means that calibre is unable to access the thumbnails directory.

[PeterT]

Originally Posted by DNSB

The 2024 Kindle devices use MTP and do not expose the system directory over a USB connection. This means that calibre is unable to access the thumbnails directory.

I'm confused though. If the user was able to add an image with the correct UUID I presume this would have been either by command line or a file explorer interface, either of which would still be using the underlying MTP connection ...

Sent from my Pixel 7a using Tapatalk

[DNSB]

As far as I know, the issue is that calibre can no longer access the thumbnails directory so you need to rely on Amazon for the correct cover thumbnails. So far the best solution seems to be sending azw3 files with the cdetype set to PDOC.

[jhowell]

Originally Posted by lasyan3

I know this error is linked because when I manually add a jpg file in the system/thumbnails folder, with the right guid, the cover show in the device.

How are you doing that? (As others have stated, the 2024 Kindle models do not appear to provide access to the system folder.)

[lasyan3]

Originally Posted by jhowell

How are you doing that? (As others have stated, the 2024 Kindle models do not appear to provide access to the system folder.)

Well I can access the internal storage of the Kindle and from there I go into system/thumbnails folder: screenshot

[lasyan3]

Originally Posted by DNSB

So far the best solution seems to be sending azw3 files with the cdetype set to PDOC.

Thanks for the tip, I want to try that but I don't see the option from the conversion windows from epub to azw3 (I can see it if I choose mobi format though).

[lasyan3]

By the way the firmware version is 5.17.1.0.4

[theducks]

Originally Posted by lasyan3

Thanks for the tip, I want to try that but I don't see the option from the conversion windows from epub to azw3 (I can see it if I choose mobi format though).

You may have set this tweak some time ago...

ID: restrict_output_formats

Restrict the list of available output formats in the conversion dialogs. For example, if you only want to convert to EPUB and AZW3, change this to restrict_output_formats = ['EPUB', 'AZW3']. The default value of None causes all available output formats to be present.

[lasyan3]

Originally Posted by theducks

You may have set this tweak some time ago...

Sorry I miswrite, I meant I see the format AZW3 in the conversion window (I never restricted the formats) but I don't see any option to change the personal doc tag in the "AZW3 output" tab (like for MOBI output).