v0.9.10 is the last version of Sigil that used the older Qt (5.6.2) and the community version of QtWebKit. It was after that where we went to Qt5.11.x and the Annulen WebKit experiment (versions 0.9.11 - 0.9.14).
For Windows users who don't want to upgrade into the later buggy QtWebKit versions (or the newest versions without Book View), I would actually recommend using my
Legacy Windows Release of v0.9.13 if you're going to stick with it for a while. It has all the features of Sigil 0.9.13, while using Qt(QtWebKit)5.6.2. It's built with Visual Studio 2013 Community Edition, and the online update-checker has been disabled. Yes it's only 32-bit, but that's so rarely (if ever) going to matter with normal Sigil usage. Some plugins that are upgraded to utilize features beyond Sigil v0.9.13 (and beyond v1.0) might be unavailable to you, though.
It should work on XP, Vista, W7, W8(.1) and W10.
The source code used to make the release is:
tag 0.9.13 of that same repository/branch