I've upgraded dlls in my project to newest version 2011.3.1116.1040 and get an error with control  QuickAccessToolBar & RadRibbonSplitButton.
'RadRibbonSplitButton' is ambiguous in the namespace 'Telerik.Windows.Controls'.
'QuickAccessToolBar' is ambiguous in the namespace 'Telerik.Windows.Controls'.

You changed these 2 controls in this version?
How can I fix this error?

Hello Hvduc,

With the Q2 official release we added a new implementation of the ribbon control in our suite of controls. The new RadRibbonView control implementation is in the Telerik.Windows.Controls.RibbonVIew.dll. However, since the RadRibbonBar and RadRibbonView controls share the same API, the same classes are defined in the Telerik.Windows.Controls.RibbonVIew.dll and the Telerik.Windows.Controls.RibbonBar.dll.

This is why I'd suggest you adding a reference to only one of those assemblies in your solution based on the controls you're using. You can read more information about the differences between the RadRibbonView and RadRibbonBar controls here.

Best wishes,
Tina Stancheva
the Telerik team