No new page on application using QtWebEngine and black screen.

[subzero255]

Hi,
I have an application which basically is a copy of the browser example.
That application connects also via socket to another server and as soon as it received a message from that server it opens the right page.

When using load a new page in a new tab, I receive this error:

[ERROR] [QT] GDI::createContext: wglShareLists() failed. () ((null):0, (null))
[DEBUG] [QT] QOpenGLFramebufferObject: Unsupported framebuffer format. ((null):0, (null))

And no page is loaded.
Also, while closing some tabs, the full application becomes all black and only thing possible is to close it.

What is the error and how can I fix it ?