In this situation:
- An edition has a cover image but no edition language set.
- This is the only edition of a work (or all the editions are in this case).
- The work is part of a series.
When going on the series page, the work is shown without the cover image. I haven’t checked, but maybe there’re other places where where the cover doesn’t appear (author page? series preview thumbnail? etc)
That can notably happen for books without text, that don’t have a language. Or for books where the language data has no been set for some reason.
I know Inventaire does some logic to find the cover matching the user language. But if nothing matches, but there’s at least a cover image set in one edition, I think it should fallback showing an image, any of them if there’s several to choose from, rather than showing nothing.