I'm working on a Qt desktop C++ application, based on Qt 5.15.2 (which I know is very old, it will move to Qt 6.8 in a couple of months). I'm facing an issue in Windows with several customers reporting a freeze at application start, as soon as we try to display a web page in the internal web browser. This freeze is not systematic and appears ~50% of the time. Of course, I tried to reproduce it on several Windows machines with no luck so far (else it would have been too simple :P).

I'd like to know if you'd have some recommendations about how to investigate this case more in depth, especially in this complicated context where I don't have access to a machine to reproduce the issue. Any information about known issues (like linked to graphic drivers and/or OS updates) would also be very appreciated.

Thanks in advance.

PS: I put it as a side note, as I'm not sure yet whether it is linked, but I've seen logs like this ones on some of the impacted machines: "Qt internal: Release of profile requested but WebEnginePage still not deleted. Expect troubles !". Do you think that it could be linked to that, with potentially "corrupted" temporary files being read again when starting the app?