Kavita KOReader sync issue

[Aodhagan]

What happened?

Just installed Kavita running version: v0.8.9.1-ls101 (LinuxServer) on Ubuntu 24.04 LTS.

Im trying to sync progress with my KOReader (latest version) installed on my Boox Note Air 2.

I setup OPDS following docs without problems. Following the KOReader setup guide

1. I setup a new Auth Key with no expiry date.
2. Set KOReader sync server URL to https://myserver/api/koreader/AUTH-KEY
3. Registered/logged in successfully from KOReader
4. Downloaded an EPUB via OPDS catalog in KOReader
5. Attempted to push progress after skipping a few pages - got "something went wrong with sync" error
6. Attempted to pull progress - also returns 400
7. Rescanned library, created another brand new Auth Key, repeated all steps — same result

Regarding server URL I've tried both URLs going through my reverse proxy https://myserver... and bypassing reverse proxy with http://192.168..... Both result in the same errors

Logs show
[Debug] API.Services.KoreaderService Saving Koreader progress for User (1): /body/DocFragment[9]/body/div/h1[1]/text().0 [Information] HTTP PUT /api/koreader/AUTH-KEY/syncs/progress responded 400 [Information] HTTP GET /api/koreader/AUTH-KEY/syncs/progress/9cea3884a392d8546601a574d7c23112 responded 400.

May be related to Issue #3928?

What did you expect?

Progress on book updated on Kavita server after pushing progress via progress sync on KOReader

Kavita Version Number - If you don't see your version number listed, please update Kavita and see if your issue still persists.

0.8.9.1 - Stable

Are you accessing kavita through a reverse proxy? If yes, confirm that the issue persists with a direct connection

Yes

What operating system is Kavita being hosted from?

None

If the issue is being seen on Desktop, what OS are you running where you see the issue?

None

If the issue is being seen in the UI, what browsers are you seeing the problem on?

No response

If the issue is being seen on Mobile, what OS are you running where you see the issue?

None

If the issue is being seen on the Mobile UI, what browsers are you seeing the problem on?

No response

Relevant log output

Additional Notes

No response

[majora2007]

I just want to make sure, if you had an existing library, please ensure you did a forced scan (library or series scan).

if you open the book/volume page, you should see the hash in (). This indicates that it is Kobo sync ready.

[Aodhagan]

I tried a force scan and I could see the hash on the file page as 9E6I93D283A8A490BC68501F3E4BC63F.

However, the hashes KOReader sends don't match. I re-downloaded the book via OPDS after the force scan and tried multiple times each attempt sends a different hash that doesn't match the one on Kavita quoted above e.g.

• KOReader hash attempt 1: 9cea3884a392d8546601a574d7c23112 (downloaded book before force scan mentioned above)
• KOReader hash attempt 2: 53109a59f5c80f21f85c70667d1da4a1 (re-downloaded after force scan)
• KOReader hash attempt 3: c653bb256c4bc59545ff6da87e793c5d (downloaded alternate OPDS option - i tried both of the two available options of the book)

All push/pull attempts still return 400 in the logs.
[Kavita] [2026-03-13 13:51:22.924 +00:00 63] [Information] Serilog.AspNetCore.RequestLoggingMiddleware HTTP GET /api/koreader/4Ar7CkiL/syncs/progress/c653bb256c4bc59545ff6da87e793c5d responded 400 in 2.4949 ms

[majora2007]

Wanna shoot me over the file? I can test on my setup and see if there is something just with the book or actually something strange in my logic. I tested the hell out of this last release, so a bit shocked to see an issue.

[Aodhagan]

Hmm, given what you say perhaps it's an issue with my setup rather than a bug in Kavita.

Well here's the epub in question. Sorry had to compress it first as github wont let me upload epubs.

Gary Taubes - The Case Against Sugar.zip

[majora2007]

Thanks, I grabbed it. You never know with epubs and KOReader. I'll take a look later.

[Fesaa]

Heya, I've downloaded your book and scanned my library, and it's pushing & pulling correctly. You can try using nightly to see if the behaviour persists for you. Thank you!

Some documentation on how to use our nightly builds
https://wiki.kavitareader.com/installation/docker/dockerhub/#nightly-branch

[SegaBluberry]

Hello everyone! I just wanted to add my finding here in case it helps anyone. I noticed KOReader progress sync -> Document matching method was set to Filename. I'm assuming that was the default at some point as I have used KOReader for many years.

Its not on the Kavita wiki to ensure the document matching method is set to binary that I could see, for the hash to used. Turns out that was my only problem lol.

Had the same error logs and issues as @Aodhagan