How to fix corrupted PDF

Vdubaj · 2025-10-03T05:00:52+00:00

I'm began having issues with one PDF freezing up in my Boox ereader (not on my PC or cloud). The pdf has been fine up until recently, but now everything freezes when I try to annotate. It seems that the PDF is corrupted.

How do I fix the corrupted PDF and preserve my existing annotations?

I've tried resaving the file, but uploading it from my PC does not seem to override the cloud version. If I delete the cloud version I lose the file in all my devices along with the annotations.

dstillman · 2025-10-03T05:01:25+00:00

Do you mean in the Zotero Android app, or the native Boox reader? We don’t have anything to do with the Boox reader, so you’d have to ask them for that.

Vdubaj · 2025-10-05T22:22:46+00:00

Thanks dstillman,

Based on what I've been reading, I think that it is a problem with the pdf. I've noticed now that the same PDF also freezes on my phone using the Zotero app. Other PDFs are perfectly fine on both devices (Phone and Boox reader).

I'm trying to work out how to fix or replace the corrupted pdf.

The suggestions I've come across seem to be for older Zotero versions as the instructions seem outdated. One such instruction was to resave the pdf in desktop, but doing so does not seem to updated in the cloud. The based on the stated 'Modified Time' of the online pdf.

dstillman · 2025-10-06T17:28:13+00:00

If the local file modification date changes, Zotero should re-upload the file if you click the Sync button. You can also of course just add the PDF as a new attachment.