QWebEngineView fails

[allenck]

I am trying to convert my application to use QWebEngineView instead of QWebView. I have successfully gotten the upgraded app to run with no problems on Ubuntu (12.04) and Qt 5.7.0. However, on Windows 7, and Qt 5.7.0, I get these errors and nothing is displayed in the widget:

I am using MSVC2013. Both the 32 bit and 64 bit versions of QT fail in the same way

[0730/151202:ERROR:scoped_ole_initializer.cc(20)] Multiple OleInitialize() calls for thread 1176
.
.
.
[0730/151328:ERROR:gles2_cmd_decoder.cc(2109)] [.CommandBufferContext.RenderWorker-0000000004279B90]GL ERROR :GL_INVALID_ENUM : BackFramebuffer::Destroy: <- error from previous GL command
[0730/151329:ERROR:gles2_cmd_decoder.cc(2109)] [GroupMarkerNotSet(crbug.com/242999)!:A87AC13300000000]GL ERROR :GL_INVALID_ENUM : BackFramebuffer::Destroy: <- error from previous GL command

I have successfully compiled and executed the Qt example demobrowser app so I don't think there is a problem with my Windows or QT environment.

Update: I just compiled my app under 5.6.1 and there are no problems; the app works as expected so this problem only exists in 5.7.0 and Windows MSCV2013.

Can anybody give me a clue as to what the problem may be?