When loading .NET dlls using QAxObject it will cause the webkit engine to crash in weird ways later on in the program.

Here is the fancy browser's main.cpp source modified to exhibit the issue.

int main(int argc, char * argv[])
{
    QApplication app(argc, argv);
    QAxObject *activeX1;

    activeX1 = new QAxObject();
    activeX1->setControl( "{00B01B2E-B1FE-33A6-AD40-57DE8358DC7D}");


    //Will crash when the webkit engine starts running.

    QUrl url;
    if (argc > 1)
        url = QUrl::fromUserInput(argv[1]);
    else
        url = QUrl("http://www.google.com/ncr");
    MainWindow *browser = new MainWindow(url);
    browser->show();

    return app.exec();
}

I've included the full source and a .NET dll. Register the dll using regasm to test. All of my .net dlls cannot be used with Qt because of this bug.

Everything worked fine Qt 5.0.2. It is after I upgraded to Qt 5.2.1 that it started.

Note: Furthermore, you could reproduce the issue by just calling the CoCreateInstance win32api directly instead of using the QAxObject.

However using VB6 activex dlls is fine. no crash.