Available in LIB version: 2016.3.1212

If you have a RadRibbonTab with two RadRibbonGroups and the RadRibbonView is minimized, the groups will be collapsed even if you set their default variant to Large.

Will be available in Q1 2015 Release.

The RibbonGroup displays a white border on mouse over around its Image element when the group is in collapsed state when a Windows8 theme is applied.

The RibbonView ContextualGroup is not redrawn when a new RadTabItem is added dynamically and the ContextualGroup is currently active.

Text improperly aligned for all RibbonView buttons

In Windows8 theme, the selected Contextual RibbonTab has an inner border which has to be removed to indicate the selection properly.

When the Ribbon is hosted in a RibbonWindow, the ContextualGroups are rended differently Q3 2013 release.

RibbonView: RadRibbonButton has inconsistent pressed/focused state

The styling in the controls vary when the mouse is down.
- RadRibbonButton gets a black border.
- RadRibbonSplitButton gets an dark orange border (when clicking the dropdown button)
- RadRibbonDropDownButton gets a grey line at the top

On mouse over
- RadRibbonButton and RadRibbonDropDownButton have a dark orange border with a white inner border
- RadRibbonSplitButton (dropdown button) does not get the white inner border

Reason for declination: 
Currently there is no way to unify the pressed state of these buttons because there is no Pressed state of RadSplitButton (the toggle and button parts has their own press visualization that comes from the default style of the corresponding buttons). 

If you place a TextBlock in the QuickAccessToolbar and the Ofice_Black theme is applied you get black foreground on black background which makes the text unreadable. The content of the QAT must respect the theme applied to the RadRibbonView control.

NullReferenceException design-time exception is thrown in VS designer when the RadRibbonTab is defined as a root element of a UserControl.

Setting Button, TextBlock, TextBox or any other UI Element as a Header of RadRibbonGroup produces a runtime exception: The Element is Already Child of another visual.

When UserControls are dynamically added in the RibbonView Items collection, they are displayed as RibbonTab Headers. Instead they should create a RibbonTab collection where each control represents the content of a RibbonTab.

UPDATE: An implicit style can not be applied on derived controls as their TargetType is different than the one defined in the implicit style. Basically if you set the style implicitly, the style is applied only on the types that match the TargetType exactly and not on elements derived from the TargetType value. You can find more information on the topic in the remarks section of the Style property definition: http://msdn.microsoft.com/en-us/library/system.windows.style%28VS.95%29.aspx

This is why in order to apply a Telerik predefined style on a UserControl deriving from RadRibbonTab, you  need to add a Style targeting the UserControl type in the Resources of the application. It is best to define that style after merging the Telerik ResourseDictionaries so that you can base the UserControl Style on the predefined "RadRibbonTabStyle".

When you set the Content and the Image properties of the RadGalleryItem, they get on top of each other.

There is a flickering when the active ContextualGroup is changed - the RibbonView first selects the non-contextual main tab before it switches to the according contextual tab. The flickering can't be observed every time.

There are three errors for missing icons when implicit themes are used:
Resource '/Telerik.Windows.Controls.RibbonView;component/HelpIcon.png' was not found.
Resource '/Telerik.Windows.Controls.RibbonView;component/RibbonGalleryCollapsedIcon.png' was not f

We have a RadRibbonView with enabled KeyTips and a RadComboBox control below it.
We focus the RadComboBox and press "Alt + DownArrow". As a result the the RadComboBox is opened and immediately closed and KeyTip is activated and shown and the coressponding RadRibbonTab gets the focus. The expected result is that the RadComboBox is opened, remains opened and no KeyTips are activated.

Available in LIB version: 2015.1.0604

When a view doesn't specify DesignHeight/Width, the RibbonView throws design-time exception if it contains ContextualGroups.

Expose a property to control the visibility of the background behind the RibbonTab.Headers

UPDATE: The RadRibbonView's Background property can be used to set a color behind the RadRibbonTabs