[KevinH]

But later on in that crashdump it says Sigil is using Qt 6.7.2. But the latest Sigil 2.6.0 is built with Qt 6.8.2.

So something is very strange as the wrong Qt version is in memory?

Please do a fresh clean reinstall of Sigil 2.6.0 and generate another Crashdump and post it here to verify what is crashing and most importantly why?

I edited your earlier post and to wrap it in spoiler tags because of its length.