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

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. 

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.

In the Crystal theme, the TitleBarBackground property is set through a style trigger to a static value. This leads to an unexpected result in the dark variation of the theme. 

As a workaround you can use the following style:

  <Style TargetType="telerik:RadRibbonView" BasedOn="{StaticResource RadRibbonViewStyle}">
            <Style.Triggers>
                <Trigger Property="IsHostedInRibbonWindow" Value="True">
                    <Setter Property="TitleBarBackground" Value="{telerik:CrystalResource ResourceKey=AlternativeBrush}"/>
                </Trigger>
            </Style.Triggers>
   </Style>

 

 

Scheduled for:
The fix for this issue will be available with LIB (version 2019.1.121) scheduled for publishing on Monday, 21st January 2019.

This is reproducible only in the FluentTheme. Setting the RadCollapsiblePanel.SmallButtonsPerColumn to 3 does not make any difference.  

The workaround is to set a higher value for the ContentHeight property of RadRibbonView, for example 120px.

The fix for this issue will be available with LIB (version 2018.3.1203) published on Monday, 3-rd December, 2018. 
 

Workaround for this bug is setting Style.Triggers for this scenario.

<Style BasedOn="{StaticResource RadRibbonSplitButtonStyle}" TargetType="telerik:RadRibbonSplitButton">
  <Style.Triggers>
    <MultiTrigger>
      <MultiTrigger.Conditions>
        <Condition Property="IsChecked" Value="True"/>
        <Condition Property="IsEnabled" Value="True"/>
        <Condition Property="CurrentSize" Value="Medium"/>
      </MultiTrigger.Conditions>
      <MultiTrigger.Setters>
        <Setter Property="Foreground" Value="{DynamicResource CheckedBrush}"/>
      </MultiTrigger.Setters>
    </MultiTrigger>
  </Style.Triggers>
</Style>

The current workaround is to handle the RadTabItems' PreviewMouseLeftButtonDown event like so:

         public MainWindow()
        {
            InitializeComponent();
            EventManager.RegisterClassHandler(typeof(RadRibbonTab), PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(OnClick), true);
        }

        private void OnClick(object sender, MouseButtonEventArgs e)
        {
            var tab = sender as RadRibbonTab;
            var ribbon = tab.ParentOfType<RadRibbonView>();
            if (ribbon.IsApplicationMenuOpen)
            {
                ribbon.SelectedItem = tab;
            }
        }

This is tested and reproducible in the Office2016 and Material themes. Probably it can be reproduced also with other new themes which use glyphs.

The CPU goes high because the RadRibbonGroup contains a GroupChrome element which has a TextBlock with the GlyphAdorner.ShowGlyphInDesignTime property set to True. 

To resolve this:

1.Extract the ControlTemplate of the RadRibbonGroup control.
2.Extract the ControlTemplate of the GroupChrome control.
3.Find the TextBlock element in the GroupChrome ControlTemplate.
4.Remove the telerik:GlyphAdorner.ShowGlyphInDesignTime  setting from the TextBlock
5.Set the Template of the GroupChrome in the RadRibbonGroup ControlTemplate to the custom GroupChrome template.
6.Apply the custom RadRibbonGroup template. 

As a workaround, you can set the FocusVisualStyle of the DropDownPopupContent element in the template of the RadRibbonDropDownButton  to null or add an implicit style for ContentControl setting the FocusVisualStyle to null.