SoftwareGL crashes or fails on some systems

Same root problem on a specific computer, but different symptoms depending on the app:

a) Using our application (using Qt 5.9.2), which opens a QWebEngineView using SoftwareGL, we get a dialog "Failed to create OpenGL context for format QSurfaceFormat [...] Install a driver providing OpenGL 2.0 or higher..."  [See attached qargError.png for full text.]The thing is, this computer DOES have OpenGL 4.5 installed, and it works fine for both Desktop and OpenGL ES (Angle) modes. Only SoftwareGL fails.

The same issue (with different symptoms) is reproducible in Qt demos.

b) Qt Cube OpenGL ES 2.0 example (Qt 5.9.5)

Modify the demo to use SoftwareGL like so:

int main(int argc, char *argv[])

{

    QApplication app(argc, argv); 

    QCoreApplication::setAttribute( Qt::AA_UseSoftwareOpenGL ); 

    QSurfaceFormat format; format.setDepthBufferSize(24); 

    QSurfaceFormat::setDefaultFormat(format);

    format.setRenderableType( QSurfaceFormat::OpenGL );

    QSurfaceFormat::setDefaultFormat( format );

Built in 64-bit Release using Qt Creator, using Visual Studio 2017 runtime, packaged with windeployqt.

c) Qt WebEngine Demo Browser Example (Qt 5.9.5)

Modify using code similar to above to use SoftwareOpenGL.

I have tested these same applications on a variety of other hardware (and VMWare) setups, and so far this is the first time we have seen SoftwareGL fail. (There are many other corner cases - particularly under VMWare, where DesktopGL or OpenGL ES (Angle) fail.) All demos above work on this particular computer when using DesktopGL or OpenGL ES (Angle).

As such, the environment (see below) is particularly important for reproducing this.

We actually have TWO computers that (a) through (c) above all fail on, with identical results. However, both computers have identical specs (same version of Windows, same graphics cards), so this is not a surprise.