I had a similar problem.
You can try to fix in this way:
do enable console loggin' adding CONFIG += console into the .pro file
rebuild and launch again the application: now every qDebug() message and other errors appear in a terminal
now you can follow what QT is saying that is missing (in my case libEGL.dll libGLESv2.dll and opengl32sw.dll)
QtWebEngine is a very new module and since this forum is community driven, it'll need some time to build the knowledge around it. You can also check the interest mailing list for help.
If you mean command-line parameters perhaps the answer here could shed a light...
http://forum.qt.io/topic/52375/qwebengine-how-to-disable-chrome-sandbox-using-quicknanobrowser-qt5-4-1