Black QWebEngineView widget on Windows 7 x64

When executing an application with QWebEngineView, the widget always appears black (e.g "Fancy Browser' or "Tab Browser" ). No webpage is visible.

Apps compiled with Qt 5.4.1 and msvc1013 on Windows 8.1. Visual C++ Redistributable Packages for Visual Studio 2013 were installed on target machines.

Couple of observations:

• The effect is the same as on a Virtualbox virtual machine (Windows 7 x64).
• Applications run fine on Windows 8.1
• When run on a different Windows 7 x64 system (Nvidia graphics), the apps work, but page loading is very slow (fast page load = 1s, slow = 30s - 60s) or they widget freezes (the rest of the app works).

The issue was mentioned in the following bug reports:
https://bugreports.qt.io/browse/QTBUG-43110
https://bugreports.qt.io/browse/QTBUG-42083
https://bugreports.qt.io/browse/QTBUG-44122
https://bugreports.qt.io/browse/QTBUG-45122
https://bugreports.qt.io/browse/QTBUG-43351

Why does it work or almost work on different machines with the same operating system? Does it have sth to do with GPUs and graphic drivers?