[narcessaxx]

Originally Posted by DNSB

Where are the books stored? On a local hard drive/USB driver or on a network/cloud storage? Do you see any issues when you run Library maintenance => Check library?



DRM removal is only done during the import process. You would have to delete the books from calibre and re-import them if DRM was the issue.

The books were stored in iCloud but always downloaded. I have just moved them to the local drive, though, just in case that was the issue.

I tried deleting one of the books and re-importing it. I got another error message after trying to convert to kepub.

Spoiler:

Convert book 1 of 1 (Witchmark)
DeDRM v10.0.2: Trying to decrypt kfvyfukr.epub
DeDRM v10.0.2: Verifying zip archive integrity
DeDRM v10.0.2: “kfvyfukr.epub” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub
DeDRM v10.0.2: Finished after 0.6 seconds
Integration status: True
Initialized urlfixer
Conversion options changed from defaults:
flow_size: 1040
cover: '/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/8nsra09d.jpeg'
output_profile: 'tablet'
verbose: 2
read_metadata_from_opf: '/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/o1qko7qk.opf'
Resolved conversion options
calibre version: 5.36.0
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'change_justification': 'original',
'chapter': "//*[((name()='h1' or name()='h2') and re:test(., "
"'\\s*((chapter|book|section|part)\\s+)|((prolog|p rologue|epilogue)(\\s+|$))', "
"'i')) or @class = 'chapter']",
'chapter_mark': 'pagebreak',
'comments': None,
'cover': '/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/8nsra09d.jpeg',
'debug_pipeline': None,
'dehyphenate': True,
'delete_blank_paragraphs': True,
'disable_font_rescaling': False,
'dont_split_on_page_breaks': False,
'duplicate_links_in_toc': False,
'embed_all_fonts': False,
'embed_font_family': None,
'enable_heuristics': False,
'epub_flatten': False,
'epub_inline_toc': False,
'epub_toc_at_end': False,
'epub_version': '3',
'expand_css': False,
'extra_css': None,
'extract_to': None,
'filter_css': '',
'fix_indents': True,
'flow_size': 1040,
'font_size_mapping': None,
'format_scene_breaks': True,
'html_unwrap_factor': 0.4,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x11e34de20>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': False,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': False,
'kepub_clean_markup': True,
'kepub_disable_hyphenation': False,
'kepub_hyphenate': True,
'kepub_hyphenate_chars': 6,
'kepub_hyphenate_chars_after': 3,
'kepub_hyphenate_chars_before': 3,
'kepub_hyphenate_limit_lines': 2,
'language': None,
'level1_toc': None,
'level2_toc': None,
'level3_toc': None,
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'markup_chapter_headings': True,
'max_toc_links': 50,
'minimum_line_height': 120.0,
'no_chapters_in_toc': False,
'no_default_epub_cover': False,
'no_inline_navbars': False,
'no_svg_cover': False,
'output_profile': <calibre.customize.profiles.TabletOutput object at 0x11e3cb3a0>,
'page_breaks_before': '/',
'prefer_metadata_cover': False,
'preserve_cover_aspect_ratio': False,
'pretty_print': True,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': '/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/o1qko7qk.opf',
'remove_fake_margins': True,
'remove_first_image': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'renumber_headings': True,
'replace_scene_breaks': '',
'search_replace': '[]',
'series': None,
'series_index': None,
'smarten_punctuation': False,
'sr1_replace': None,
'sr1_search': None,
'sr2_replace': None,
'sr2_search': None,
'sr3_replace': None,
'sr3_search': None,
'start_reading_at': None,
'subset_embedded_fonts': False,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 6,
'toc_title': None,
'transform_css_rules': '[]',
'transform_html_rules': '[]',
'unsmarten_punctuation': False,
'unwrap_lines': True,
'use_auto_toc': False,
'verbose': 2}
DeDRM v10.0.2: Trying to decrypt wg_6ozxn.epub
DeDRM v10.0.2: Verifying zip archive integrity
DeDRM v10.0.2: “wg_6ozxn.epub” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub
DeDRM v10.0.2: Finished after 0.5 seconds
InputFormatPlugin: EPUB Input running
on /var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/8l955x5u.epub
Failed to parse as XML, parsing as tag soup
Traceback (most recent call last):
File "calibre/ebooks/oeb/polish/parsing.py", line 81, in parse
ValueError: Root tag is not <html> in the XHTML namespace

Parsing all content...
Parsing chapter19.xhtml ...
Parsing chapter20.xhtml ...
Parsing chapter22.xhtml ...
Parsing acknowledgments.xhtml ...
Parsing chapter15.xhtml ...
Parsing chapter18.xhtml ...
Parsing chapter25.xhtml ...
Parsing chapter7.xhtml ...
Parsing dedication.xhtml ...
Parsing styles/stylesheet.css ...
Parsing chapter2.xhtml ...
Parsing copyright.xhtml ...
Parsing chapter12.xhtml ...
Parsing chapter14.xhtml ...
Parsing chapter21.xhtml ...
Parsing contents.xhtml ...
Parsing newsletter.xhtml ...
Parsing torad.xhtml ...
Parsing chapter1.xhtml ...
Parsing chapter13.xhtml ...
Parsing chapter9.xhtml ...
Parsing cover.xhtml ...
Parsing mini_toc.xhtml ...
Parsing title.xhtml ...
Parsing toc.xhtml ...
Parsing abouttheauthor.xhtml ...
Parsing chapter23.xhtml ...
Parsing chapter4.xhtml ...
Parsing chapter5.xhtml ...
Parsing chapter6.xhtml ...
Parsing chapter10.xhtml ...
Parsing chapter16.xhtml ...
Parsing chapter24.xhtml ...
Parsing chapter3.xhtml ...
Parsing chapter11.xhtml ...
Parsing chapter17.xhtml ...
Parsing chapter8.xhtml ...
Parsing copyrightnotice.xhtml ...
The item toc.xhtml is not a XML document. Removing it from spine.
Reading TOC from HTML...
Found image encoded as data URI converting it to normal image
Found image encoded as data URI converting it to normal image
Found image encoded as data URI converting it to normal image
Found image encoded as data URI converting it to normal image
Found image encoded as data URI converting it to normal image
Found image encoded as data URI converting it to normal image
Found image encoded as data URI converting it to normal image
Merging user specified metadata...
Detecting structure...
Flattening CSS and remapping font sizes...
Source base font size is 11.60400pt
Removing fake margins...
Found 34 items of level: div_1
Found 4323 items of level: p_2
div_1 left margin stats: Counter({'0': 30})
div_1 right margin stats: Counter({'0': 30})
p_2 left margin stats: Counter({'0': 4323})
p_2 right margin stats: Counter({'0': 4323})
Cleaning up manifest...
Trimming unused files from manifest...
Trimming 'images/Title-Page.jpg' from manifest
Trimming 'torad.xhtml' from manifest
Trimming 'mini_toc.xhtml' from manifest
Trimming 'images/twitter_logo.png' from manifest
Trimming 'images/backad.jpg' from manifest
Trimming 'images/NewsletterSignup.jpg' from manifest
Trimming 'images/author-photo.jpg' from manifest
Creating KePub Output...
2022-02-16 13:11:29 [DEBUG] Running ePub conversion
Splitting markup on page breaks and flow limits, if any...
Looking for large trees in chapter19.xhtml...
No large trees found
Looking for large trees in chapter20.xhtml...
No large trees found
Looking for large trees in chapter22.xhtml...
No large trees found
Looking for large trees in acknowledgments.xhtml...
No large trees found
Looking for large trees in chapter15.xhtml...
No large trees found
Looking for large trees in chapter18.xhtml...
No large trees found
Looking for large trees in chapter25.xhtml...
No large trees found
Looking for large trees in chapter7.xhtml...
No large trees found
Looking for large trees in dedication.xhtml...
No large trees found
Looking for large trees in chapter2.xhtml...
No large trees found
Looking for large trees in copyright.xhtml...
No large trees found
Looking for large trees in chapter12.xhtml...
No large trees found
Looking for large trees in chapter14.xhtml...
No large trees found
Looking for large trees in chapter21.xhtml...
No large trees found
Looking for large trees in contents.xhtml...
No large trees found
Looking for large trees in newsletter.xhtml...
No large trees found
Looking for large trees in chapter1.xhtml...
No large trees found
Looking for large trees in chapter13.xhtml...
No large trees found
Looking for large trees in chapter9.xhtml...
No large trees found
Looking for large trees in cover.xhtml...
No large trees found
Looking for large trees in title.xhtml...
No large trees found
Looking for large trees in abouttheauthor.xhtml...
No large trees found
Looking for large trees in chapter23.xhtml...
No large trees found
Looking for large trees in chapter4.xhtml...
No large trees found
Looking for large trees in chapter5.xhtml...
No large trees found
Looking for large trees in chapter6.xhtml...
No large trees found
Looking for large trees in chapter10.xhtml...
No large trees found
Looking for large trees in chapter16.xhtml...
No large trees found
Looking for large trees in chapter24.xhtml...
No large trees found
Looking for large trees in chapter3.xhtml...
No large trees found
Looking for large trees in chapter11.xhtml...
No large trees found
Looking for large trees in chapter17.xhtml...
No large trees found
Looking for large trees in chapter8.xhtml...
No large trees found
Looking for large trees in copyrightnotice.xhtml...
No large trees found
2022-02-16 13:11:29 [WARN] This EPUB file has no Table of Contents. Creating a default TOC
2022-02-16 13:11:29 [INFO] Upgrading to EPUB 3...
2022-02-16 13:11:29 [DEBUG] Done ePub conversion
2022-02-16 13:11:29 [DEBUG] Creating KePub Container for ePub at /var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/ftohtvkw.kepub
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file titlepage.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file cover.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file title.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file copyrightnotice.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file dedication.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter1.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter2.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter3.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter4.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter5.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter6.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter7.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter8.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter9.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter10.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter11.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter12.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter13.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter14.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter15.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter16.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter17.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter18.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter19.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter20.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter21.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter22.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter23.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter24.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file chapter25.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file acknowledgments.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file abouttheauthor.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file newsletter.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file contents.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file copyright.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file toc.xhtml
2022-02-16 13:11:29 [DEBUG] Forcing cleanup for file nav.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file titlepage.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file cover.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file title.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file copyrightnotice.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file dedication.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter1.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter2.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter3.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter4.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter6.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter5.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter8.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter10.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter7.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter11.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter12.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter13.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter9.xhtml
2022-02-16 13:11:29 [DEBUG] Cleaning markup for file chapter14.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter15.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter16.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter18.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter17.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter19.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter20.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter21.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter22.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter23.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter24.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file chapter25.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file acknowledgments.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file abouttheauthor.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file newsletter.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file contents.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file copyright.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file toc.xhtml
2022-02-16 13:11:30 [DEBUG] Cleaning markup for file nav.xhtml
2022-02-16 13:11:30 [INFO] Copying file '/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/r3ycbvpp_KePubOutputPluginInfo' to '/private/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/5veaqfbg_epub_container' as 'plugininfo.kte'
2022-02-16 13:11:30 [DEBUG] Found meta node with name=cover
2022-02-16 13:11:30 [INFO] Found cover image ID 'cover'
2022-02-16 13:11:30 [DEBUG] Found an item node with cover ID
2022-02-16 13:11:30 [WARN] Item node is already set as cover-image
2022-02-16 13:11:30 [INFO] Copying file '/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/kepub_ye69r9ke_hyphenate' to '/private/var/folders/3z/8lg296rs79l9zdlc17r6456w0000gn/C/calibre_5.36.0_tmp_7lirq5sr/5veaqfbg_epub_container' as 'kte-css/hyphenation.css'
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file titlepage.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file title.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file cover.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file copyrightnotice.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file dedication.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter1.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter2.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter3.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter5.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter7.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter8.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter9.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter11.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter6.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter13.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter14.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter4.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter17.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter19.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter20.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter10.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter23.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter24.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter18.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter25.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter22.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file abouttheauthor.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file newsletter.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file contents.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file toc.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter21.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file nav.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter16.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter12.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file chapter15.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file acknowledgments.xhtml
2022-02-16 13:11:30 [DEBUG] Adding reference to kte-css/hyphenation.css to file copyright.xhtml
2022-02-16 13:11:30 [ERROR] Failed converting!
Traceback (most recent call last):
File "calibre_plugins.kepubout.conversion.kepub_output" , line 188, in convert
common.modify_epub(
File "calibre_plugins.kepubout.common", line 220, in modify_epub
container.add_content_file_reference("kte-css/{0}".format(css_path))
File "calibre_plugins.kepubout.container", line 222, in add_content_file_reference
self.__run_async_over_content(self.__add_content_f ile_reference_impl, (name,))
File "calibre_plugins.kepubout.container", line 375, in __run_async_over_content
self.__run_async(func, names)
File "calibre_plugins.kepubout.container", line 368, in __run_async
future.result(timeout=10)
File "concurrent/futures/_base.py", line 432, in result
File "concurrent/futures/_base.py", line 388, in __get_result
File "concurrent/futures/thread.py", line 57, in run
File "calibre_plugins.kepubout.container", line 234, in __add_content_file_reference_impl
head = head[0]
IndexError: list index out of range

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 215, in main
File "calibre/gui2/convert/gui_conversion.py", line 38, in gui_convert_override
File "calibre/gui2/convert/gui_conversion.py", line 25, in gui_convert
File "calibre/ebooks/conversion/plumber.py", line 1281, in run
File "calibre_plugins.kepubout.conversion.kepub_output" , line 188, in convert
File "calibre_plugins.kepubout.common", line 220, in modify_epub
File "calibre_plugins.kepubout.container", line 222, in add_content_file_reference
File "calibre_plugins.kepubout.container", line 375, in __run_async_over_content
File "calibre_plugins.kepubout.container", line 368, in __run_async
File "concurrent/futures/_base.py", line 432, in result
File "concurrent/futures/_base.py", line 388, in __get_result
File "concurrent/futures/thread.py", line 57, in run
File "calibre_plugins.kepubout.container", line 234, in __add_content_file_reference_impl
IndexError: list index out of range

Am I missing something? Are the epubs themselves broken? Something could be corrupting them, but I'm not sure what.