Unable to open epub "Zip archive is not supported"

[NormanDunbar]

Linux Mint 21.1 Vera. 64 bit. All updates applied.

I have a number of purchased epub books. Xreader can open most of them, but some from as recently as 2022 fail with the error "Unable to open document. File type Zip archive (application/zip) is not supported.

Using Nemo, right-click->properties, all my epubs show "Document (application/epub+zip)" however, using the "file" command, I get different results.

Those that do open correctly are "EPUB document" while those that don't open are "Zip archive data, at least v2.0 to extract, compression method=store". I assume the latter is the source of my problems?

Is there anything I can do to be able to read my books on Linux MInt with Xreader? Thanks.

Cheers,
Norm.

[mtwebster]

I'm pretty certain those files are corrupt - I built xreader with its internal mimetype check disabled. I found an epub that had given me the same behavior as you're seeing, and it was able to be opened, but only 2 pages rendered out of 80.

I then installed Calibre, which I sort of treat as a reference app for this stuff, and it also only displayed two pages, and actually dropped all of the bad ones.

Are there other formats you can download? You could convert a pdf to epub format using calibre also.

[NormanDunbar]

Hi @mtwebster .

Thanks for a prompt reply.

I am able to read the book on my Android phone and my Android tablet with a couple of different epub readers. I also have Calibre installed (now!) and it is happy to open the file to view or even to edit, although I haven't tried actually editing the book. I also installed Foliate and it is also able to open the book but, quite honestly, I do not like Foliate at all!

Reading through with Calibre, I'm able to read all pages in the affected books.

HTH

Cheers,
Norm.

[mtwebster]

Yours must be a different 'broken' than my test file. Can you point me to one? (I'll even buy it from wherever if necessary, it would keep me from continuing to stab in the dark).

Thanks

[NormanDunbar]

If you have a (private?) space somewhere I can upload the affected book to, I can let you have my copy temporarily to see if you can fix things. The book is copyright so I'd be loathe, as an author myself, to put it somewhere public. I think fixing a problem like this is "fair use".

HTH

Cheers,
Norm.

[mtwebster]

Hi, sorry for the delayed response -

Unfortunately I don't have anything private to upload to. Would email work? I understand your concerns.

[NormanDunbar]

No worries on the delay, not a problem.
Email would be fine. Where shall I send it?

Cheers,.
Norm.