When the "Automatically Hide the taskbar in desktop mode" windows setting is enabled and the RadRibbonWindow is maximized, it exceeds the screen area. 

Implement keyboard navigation for the items in the ApplicationMenu - through arrow keys for example.

Workaround:
In the Loaded event of the RibbonWindow, use the Telerik.Windows.Controls.RibbonView.Shell.WindowChrome class to get the current window and set its ResizeBorderThickness property to 0. 

public MainWindow()
{
    InitializeComponent();
    this.Loaded += MainWindow_Loaded;
}
 
void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
    Telerik.Windows.Controls.RibbonView.Shell.WindowChrome chome = Telerik.Windows.Controls.RibbonView.Shell.WindowChrome.GetWindowChrome(this);
    chome.ResizeBorderThickness = new Thickness(0);
}

Black border appears around the window when SizeToContent is set to WidthAndHeight

1. When the RibbonWindow is maximized the draggable area ends below the WindowTitle

2. In Normal state - the draggable area could be expanded in Material, Fluent and Crystal themes

A possible workaround is to change the WindowCaptionHeight property:

RadRibbonDropDownButton DropDownIndicator isn't rotated when the DropDownButtonPosition is Right and the DropDownPlacement is Right

To reproduce this:

• Set the RadRibbonButton LargeImage/SmallImage to a property that is larger than 16 (small image) or 32 (large image).
• Set IsAutoSize to False. This will stretch the image on all available space for the button.
• Set IsAutoSize to True. This should uniform stretch the picture so that it fills the auto size of 16 or 32 pixels. However, the image doesn't stretch, instead its Stretch is set to None, which expand the image to its original size. This leads to the clipping.

To work this around, avoid setting the IsAutoSize property. Or use smaller pictures - 16 or 32 pixels.

In the application menu, we have placed a RadRibbonSplitButton. When the application menu is open, and we press Tab and Space key, the application menu is closed and the UI unresponsive until the mouse leaves the control.

The HeaderVisibility property of RadRibbonTab doesn't work when changed at runtime.

A workaround is to use Visibility property of RadRibbonTab, instead of HeaderVisibility

In some cases an InvalidOperationException is thrown when the control is loaded too early (before it is added to the visual tree). This reproduces only when the ribbon's content is minimized initially.

To work this around, you can set the IsMinimizable property of RadRibbonView to False.

 

The ribbon tab doesn't get selec if you click in the exact middle of the header of RadRibbonTab.

To work this around, extract the ControlTemplate of RadRibbonTab and move the Grid with x:Name="ContentPanel" before the Grid with x:Name="HeaderPanel".

When the RibbonBackstage is open and then a RibbonBackstageItem is clicked to close the backstage, the ApplicationButton's FluentControl pressed state effect remains visible in the Fluent theme.

We have a RadRibbonWindow.
When it is run on Windows XP (or on Windows 7, "Windows Classic" theme) and the DPI settings are high (above 170 %), the standard window buttons (Minimize, Restore and Close) are not displayed properly (they are cut). Also there is too much space between them.

When opening Backstage using KeyTips service, NullReferenceException is thrown when the backstage items have also had KeyTips set. 

When the ContentHeight is set in Xaml or before the control is loaded it is not respected. 

Every KeyTipControl is placed inside a Popup. Expose properties which could control the Popup position.

Please support the new Office Simplified Ribbon: https://support.office.com/en-us/article/use-the-simplified-ribbon-44bef9c3-295d-4092-b7f0-f471fa629a98?ui=en-US&rs=en-US&ad=US.

Currently, you can navigate through the elements of the ribbon only via the keytips or the arrow keys. Add support for the Tab key as well.

In other words when you enter the keyboard navigation mode, the Tab key should work along with the arrow keys. See Word's ribbon for a reference.