If you read on a Kobo, update. A change in v4.1.34 caused the server to throw
away every highlight your Kobo sent it, and this release stops that — along with
the older, separate problem where the Kobo deletes its own highlights after a
sync.
docker pull ghcr.io/new-usemame/calibre-web-nextgen:v4.1.36
Highlights made on a Kobo are no longer discarded by the server. Since
v4.1.34 the chapter location arriving with each highlight was validated, and the
whole highlight was thrown away when that location looked unfamiliar — the text,
the note and the colour lost over a field that is only a pointer and can be
worked out again. Some Kobo books legitimately report a location the check did
not recognise, so on an affected library every Kobo highlight was dropped, with
nothing in the interface to show it. If you are on v4.1.34 or v4.1.35 and you
highlight on a Kobo, please update.
Your Kobo no longer loses its highlights when it syncs. This one is older
than us — reporters have been chasing it upstream since 2022 without a root
cause. Every time you open a book, the Kobo asks the server what annotations
exist for it. We forwarded that question to Kobo's own cloud, which has never
heard of a book you sideloaded, so it answered "none" — the device believed it
and deleted the highlights it had. For a sideloaded book the Kobo is usually the
only copy. We now decline to answer that question for books we serve, rather than
passing on an answer that is not true.
Measured on real hardware, reading the device's own database either side of one
sync: 88 highlights before, 1 uploaded and 87 deleted after. It also explains the
workaround people found years ago — removing a book from its shelf once synced
stops the sync, so the question is never asked.
Books that silently refused to keep Kobo highlights now work. Some EPUBs,
commonly from free ebook sites, point at their table of contents with a path that
steps outside its own folder. A Kobo does not tidy that path up, so it ends up
with two different names for the same chapter: it saves your highlight under one
and looks for it under the other. The highlight stays on the device forever and
is simply never drawn — which is why highlighting can appear broken for one
particular book while every other book is fine. Converting for Kobo now tidies
those paths, leaving the book's text and its Kobo page positions untouched. On
the library where this was found, 5 books of 216 were affected, and none had ever
managed to store a single highlight.
Chapter locations containing a redundant .. are understood rather than
rejected, so those highlights land in the right place and show up in the web
reader.
The book page lists the shelves a book is on again, next to the publisher and
language, each one linking through to that shelf.
Arabic, Hebrew and Farsi titles read the right way round on the book page and
on grid and shelf cards, detected per field from the text itself.
If you have already lost highlights to this, they may not be gone: for the third
problem above the rows are still on the device and merely unmatched, which is
recoverable. The full diagnosis, including the query to tell the two cases apart,
is in notes/KOBO-HIGHLIGHT-LOSS-ROOT-CAUSE-2026-08-15.md.