We can’t understand completely how you get this assert. You say you removed and don’t call line ribbonBar()->setFrameThemeEnabled() that initializes title and the main window frame. If it is that, then object WindowHookManager mustn’t be created. So its destructor will not be called, where this assert Q_ASSERT(m_hook.size() == 0) is defined. We can’t repeat this error. Please, help us repeat this assert by our example Ribbon_Application or Ribbon_ControlsDemo and send us the modified file. We’d be sorry if we didn’t understand you properly.
I forgot to explain that I swichted from 4.12 to 5.1.
I have integrated the ribbon now exaktly like in the example application of the 5.1 examples. And now I dont't get the assert anymore.
So for me it's fine now.