Why are some html files not shown in Zotero as thumbnail (preview)?

gracesbj · 2026-08-02T10:16:52+00:00

It's very confusing: similar html files are sometimes shown as thumbnails, sometimes not.
I have no clue why this behavior of Zotero is present (version 9.0.6, 64bit), with Windows 11 (25H2). I know that the explorer is very bitchy about previews of html files, but Zotero?
Has anyone an idea?

AbeJellinek · 2026-08-03T16:03:04+00:00

Can you give an example of a snapshot that doesn't get a preview? How did you save the item?

gracesbj · 2026-08-03T16:48:53+00:00

Attached you find two screenshots. They differ re preview.
All attached html files are only linked to my bibliography, not saved in the bibliothek.

I don't understand the difference ...
these html files are all created in the same way: export of kindle ebooks markings, which results in html files.

https://s3.amazonaws.com/zotero.org/images/forums/u10829097/2q2ezcjqs1qauwp6j6qc.png
https://s3.amazonaws.com/zotero.org/images/forums/u10829097/ikagfr1q6glpyeci5s3t.png

AbeJellinek · 2026-08-03T17:11:20+00:00

Could you send the former (the one with no preview) to support@zotero.org along with a link to this thread?

AbeJellinek · 2026-08-03T22:21:42+00:00

It looks like you attached the screenshot to your email - I meant attach the HTML file itself.

gracesbj · 2026-08-05T08:01:28+00:00

sorry, I misunderstood.
But: I solved the problem with the html files!

Thanks to the forum thread https://forums.zotero.org/discussion/6019/finding-unindexed-items I could easily identify the problem html files.

It seems now that between 08/2025 and 06/2026 a version of the Kindle app (iPad) generated wrong html files during the export of my markings - there were 13 html files which I had to regenerate, export and link in Zotero.

And guess what? The indexing in Zotero was successful - all my html files in Zotero have now a preview (which means they are indexed).
So, thanks for your patience and help.