But Qt 6.7.3 is used by the older Sigil 2.4.2, not the newer 2.5.2. So your .wer crashfile might not be accurate.
I will try the same thing now that we know the exact steps to recreate the crash, but under MacOS and Linux to see if we can get a solid backtrace of the crash.
Of course, this just had to be found immediately after a release!