[jloh]

Moderator: if this is not the correct place to post this please feel free to move this post to the appropriate forum.

Hello, I finally made it here after using Calibre for a while (5+ years). But I have a general question. There are books in epub format that I can't seem to open in Calibre, but I can in fbreader.
It is an epub file and not a zip file. I can tell you that some of the fonts are missing when I open it in fbreader. Could this be due to missing fonts?

I'm using Debian Bookworm on a i7-8550U, if that helps.

Without telling you which book it is, I can give you the output of the error:

calibre, version 5.37.0
ERROR: Loading book failed: Failed to open the book at ... Click "Show details" for more info.

Failed to convert book: ... with error:
InputFormatPlugin: EPUB Input running
on ...
EPUB appears to be invalid ZIP file, trying a more forgiving ZIP parser
Failed to run pipe worker with command: from calibre.srv.render_book import viewer_main; viewer_main()
Traceback (most recent call last):
File "calibre/ebooks/conversion/plugins/epub_input.py", line 259, in convert
File "calibre/utils/zipfile.py", line 774, in __init__
File "calibre/utils/zipfile.py", line 809, in _GetContents
File "calibre/utils/zipfile.py", line 824, in _RealGetContents
calibre.utils.zipfile.BadZipfile: File is not a zip file

During handling of the above exception, another exception occurred:

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 45, in <module>
File "site.py", line 41, 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 791, in render
File "calibre/ebooks/oeb/iterator/book.py", line 62, in extract_book
File "calibre/customize/conversion.py", line 242, in __call__
File "calibre/ebooks/conversion/plugins/epub_input.py", line 266, in convert
File "calibre/utils/localunzip.py", line 252, in extractall
File "calibre/utils/localunzip.py", line 234, in _extractall
File "calibre/utils/localunzip.py", line 177, in copy_compressed_file
ValueError: Invalid ZIP file, local header is damaged