[poxi1023]

Originally Posted by DiapDealer

My first blind stab might have been fruitful!

@poxi1023, if you would try one simple change to src/MainUI/MainWindow.cpp for me, I'd appreciate it.

Change line MainWindow.cpp 247 from:

#ifdef Q_OS_MAC

to:

#ifndef Q_OS_WIN32

With that one change (from the original source), I'm able to see all the correct events/destructors firing and all the preferences get flushed to disk even when the ToC dockwidget is open when closing Sigil.

I still get the QtWebEngineWidgets segfault everytime, mind you, but F&R preferences are correctly saved.

Thank you, DiapDealer!
Your change fixed my problem!