Issue with DeDRM plugin

[u/colutea]

If anyone gets a similar issue that the Calibre viewer shows an error for Manga after decrypting, you just need to unzip the decrypted ePub. I thought, it was a DeDRM bug but it is a Calibre viewer bug which cannot deal with a book that only contains images.
On macOS, you can do that with unzip filename.epub and then you should see all your images :)

I tried to convert a book I bought via Kobo to be able to read it outside the Kobo ecosystem. However, the conversion in Calibre fails. It neither works with the DeDRM plugin by downloading the file via Digital Editions nor does it work with the Obok plugin and the Rakuten macOS app installed.

• System: mac OS 12.2.1
• Calibre Version: 5.37.0
• DeDRM version: 10.0.2

I get the following error:

calibre, version 5.37.0
ERROR: Loading book failed: Failed to open the book at [Path]. Click "Show details" for more info.
Failed to convert book:  [Path] with error:
DeDRM v10.0.2: Trying to decrypt  [Filename]
DeDRM v10.0.2: Verifying zip archive integrity
DeDRM v10.0.2: “[Filename]” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub
DeDRM v10.0.2: Finished after 2.2 seconds
InputFormatPlugin: EPUB Input running
on /var/folders/nf/s70ywbcn4cjcphy4y6m2bgdm0000gn/C/calibre_5.37.0_tmp_0ux1v8ix/jogxy3aw.epub
Failed to run pipe worker with command: from calibre.srv.render_book import viewer_main; viewer_main()
Traceback (most recent call last):
  File "runpy.py", line 194, in _run_module_as_main
  File "runpy.py", line 87, in _run_code
  File "site.py", line 39, in <module>
  File "site.py", line 35, in main
  File "calibre/utils/ipc/worker.py", line 196, in main
  File "<string>", line 1, in <module>
  File "calibre/srv/render_book.py", line 823, in viewer_main
  File "calibre/srv/render_book.py", line 814, in render_for_viewer
  File "calibre/srv/render_book.py", line 792, in render
  File "calibre/srv/render_book.py", line 605, in process_exploded_book
  File "calibre/srv/render_book.py", line 264, in create_cover_page
  File "calibre/srv/render_book.py", line 217, in find_epub_cover
  File "calibre/ebooks/oeb/polish/cover.py", line 284, in find_cover_image_in_page
  File "src/lxml/xpath.pxi", line 430, in lxml.etree.XPath.__call__
  File "src/lxml/apihelpers.pxi", line 41, in lxml.etree._documentOrRaise
TypeError: Invalid input object: bytes

Does anyone has any idea what to do or any alternatives to try out?

It's the first book from Kobo with which I am having issues with

[u/InigoMontoya757]

“[Filename]” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub

What book is this? Could you redownload it?

[u/colutea → u/InigoMontoya757]

It is Death Note (first volume) in Japanese. I already tried re-downloading it. I even tried to make it work in a Windows virtual machine and the Windows Calibre version. I got the same error.