Stange error- Spine is empty

[DragoLord19d]

calibre, version 7.8.0
ERROR: Loading book failed: Failed to open the book at C:\Users\Owner\Documents\MEGA\Calibre\AlgernonInWo nderland\Porter sur toi un nouveau regard (338)\metadata.opf. Click "Show details" for more info.

Failed to convert book: C:\Users\Owner\Documents\MEGA\Calibre\AlgernonInWo nderland\Porter sur toi un nouveau regard (338)\metadata.opf with error:
InputFormatPlugin: HTML Input running
on C:\Users\Owner\Documents\MEGA\Calibre\AlgernonInWo nderland\Porter sur toi un nouveau regard (338)\metadata.opf
Parsing all content...
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 198, in _run_module_as_main
File "runpy.py", line 88, in _run_code
File "site.py", line 95, in <module>
File "site.py", line 90, in main
File "site.py", line 50, in run_entry_point
File "calibre\utils\ipc\worker.py", line 196, in main
File "<string>", line 1, in <module>
File "calibre\srv\render_book.py", line 948, in viewer_main
File "calibre\srv\render_book.py", line 939, in render_for_viewer
File "calibre\srv\render_book.py", line 916, in render
File "calibre\ebooks\oeb\iterator\book.py", line 64, in extract_book
File "calibre\customize\conversion.py", line 245, in __call__
File "calibre\ebooks\conversion\plugins\html_input. py", line 113, in convert
File "calibre\ebooks\conversion\plumber.py", line 1336, in create_oebbook
File "calibre\ebooks\oeb\reader.py", line 97, in __call__
File "calibre\ebooks\oeb\reader.py", line 724, in _all_from_opf
File "calibre\ebooks\oeb\reader.py", line 369, in _spine_from_opf
calibre.ebooks.oeb.base.OEBError: Spine is empty

[jhowell]

From the log it appears that you are trying to open a metadata.opf file in your calibre library as if it was an actual book. It is not.

[dan418]

same problem here
mint 21.3
I'm a newbie

calibre, version 7.20.0 (linux, embedded-python: True)
Conversion error: Failed: Convert book 1 of 1 (Les baladins de la Planète Géante)

Convert book 1 of 1 (Les baladins de la Planète Géante)
DeDRM v10.0.9: Trying to decrypt 7h33lgkf.epub
DeDRM v10.0.9: Verifying zip archive integrity
DeDRM v10.0.9: Post-processing took 0.0 seconds
DeDRM v10.0.9: Finished after 0.1 seconds
Conversion options changed from defaults:
enable_heuristics: True
read_metadata_from_opf: '/tmp/calibre_7.20.0_tmp_hupitaql/n5y1ihzn.opf'
verbose: 2
cover: '/tmp/calibre_7.20.0_tmp_hupitaql/5j_4oid3.jpeg'
Resolved conversion options
calibre version: 7.20.0
{'add_alt_text_to_img': False,
'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': '/tmp/calibre_7.20.0_tmp_hupitaql/5j_4oid3.jpeg',
'debug_pipeline': None,
'dehyphenate': True,
'delete_blank_paragraphs': True,
'disable_font_rescaling': False,
'dont_compress': False,
'duplicate_links_in_toc': False,
'embed_all_fonts': False,
'embed_font_family': None,
'enable_heuristics': True,
'expand_css': False,
'extra_css': None,
'extract_to': None,
'filter_css': '',
'fix_indents': True,
'font_size_mapping': None,
'format_scene_breaks': True,
'html_unwrap_factor': 0.4,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x789870a12b10>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': False,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': False,
'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,
'mobi_toc_at_start': False,
'no_chapters_in_toc': False,
'no_inline_navbars': False,
'no_inline_toc': False,
'output_profile': <calibre.customize.profiles.OutputProfile object at 0x789870a5df50>,
'page_breaks_before': '/',
'prefer_author_sort': False,
'prefer_metadata_cover': False,
'pretty_print': False,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': '/tmp/calibre_7.20.0_tmp_hupitaql/n5y1ihzn.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,
'share_not_sync': False,
'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 v10.0.9: Trying to decrypt s27ja2jo.epub
DeDRM v10.0.9: Verifying zip archive integrity
DeDRM v10.0.9: Post-processing took 0.0 seconds
DeDRM v10.0.9: Finished after 0.0 seconds
InputFormatPlugin: EPUB Input running
on /tmp/calibre_7.20.0_tmp_hupitaql/rntz2973.epub
Found HTML cover OEBPS/Text/titlepage.xhtml
Parsing all content...
Traceback (most recent call last):
File "runpy.py", line 198, in _run_module_as_main
File "runpy.py", line 88, in _run_code
File "site.py", line 47, in <module>
File "site.py", line 43, 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 1139, in run
File "calibre/ebooks/conversion/plumber.py", line 1349, in create_oebbook
File "calibre/ebooks/oeb/reader.py", line 97, in __call__
File "calibre/ebooks/oeb/reader.py", line 726, in _all_from_opf
File "calibre/ebooks/oeb/reader.py", line 371, in _spine_from_opf
calibre.ebooks.oeb.base.OEBError: Spine is empty

but when I click on file, it says EPUB and everything is readable...?
It use to work before on mint 19.1 with calibre 5.37
just did a fresh install of mint
calibre is install from flatpack, could that be the culprit?
or one of the plugin?
thanks

[kovidgoyal]

https://www.mobileread.com/forums/sh...d.php?t=186697

[JSWolf]

Try installing the latest calibre from the official calibre site and see how that goes.