I use your company's products ribben5.4.0_msvc2017 and Docking3.2.0__msvc2017 integrated in one APP. When the APP is running, when the mouse drags the DockWidgetPanel window, an exception occurs. The location of the exception: QtnWindowTitleBar_win.cpp Line:1462 "Q_ASSERT(false)", the variable HWND winId is 0.
APP operating environment: Win10 system/VS2017 development/QT5.13.0__msvc2017 version generates ribben and Docking libraries.
However, I used QT5.13.0__MinGw64 to compile ribben5.4.0_MinGw64 and Docking3.2.0__MinGw64 to generate dynamic libraries and integrate them into the QT test software, without this abnormal problem. QT test software and APP integrate ribben and docking in the same way.
Does the error appear when you try to drag a floating window or when you rive away the dock widget panel from the main window?