Designer allows adding a MainMenu object to a Page but it never shows as it isn’t added to the Page Controls collection.
Page inherits from System.Windows.Forms.ScrollableControl and MainMenu doesn’t inherit from System.Windows.Forms.ScrollableControl as ToolBar, StatusBar and MenuBar do. In a nutshell, the Designer shouldn’t allow to add MainMenu to a Page.
This is fixed. Now MainMenu is not visible in the toolbox for Page, UserControl and Desktop, which are the other 3 root surfaces in Wisej other than Form.
You can still add a MenuBar to the page. The MenuBar acts like a MainMenu but it’s also a regular control that can dock and can be nested. It also supports AutoOverflow when resized.