Creator 2 is built against the (unstable) 4.7. The apps built with it are compiled against 4.6, so if both Creator and the target application act in the same weird way (and they didn't do that earlier) then it is likely not a bug in Qt (otherwise it'd be there with earlier versions of Qt too), more likely in some dependency of it (or something completely unrelated). I'm having freezing issues with Creator 2 beta as well (it's built against quite old revision of 4.7), different from yours though.