When move the most left pane in a split container above some other pane in the same split container the second splitter is created.

Available in LIB version 2016.3.1017, it will be also available in the 2016 R3 SP1 release. 

When used in second Tab in TabControl for example.

Available with the R3 2016 SP1 release. 

When the content of a RadPane contains an ScrollViewer it is scrolled to its end when the RadDocking control is used in nested docking scenarios.

Available with the 2015 Q3 release.

In nested RadDocking scenarios if the inner RadPane's content contains a ScrollViewer pressing "Tab" or "Tab + Shift" (keyboard navigation) the focus is moved out of the RadPane's content into the parts of the RadDocking.

When the control contains RadPane instances which Content is provided by a MAF framework that content experiences flickers and disappearing when the RadPane is being floated, docked, pinned or unpinned.

When loading a previously saved layout that includes a floated RadPane located on a currently not available monitor, that RadPane should be made visible on the available monitor.

Currently its is directly loaded in its saved location which is not visible.

While the control's DragDropMode is set to Deferred and the RadPane instances contain content which is UI heavy, dragging those RadPane instances in order to reorder or re-dock them may experience performance issues leading to sluggishness of the drag and drop action.

If an custom implementation is implemented that restores the IsActive property state if a RadPane during the control's LoadLayout functionality the "Active" visual state if that RadPane instance is not cleared if different RadPane is selected.

This issue could be observed in the VisualStudioDocking located in the XAML GitHub repository here: https://github.com/telerik/xaml-sdk/tree/master/Docking/VisualStudioDocking

This also causes the initial DataContext to be left out in the memory.
Available in LIB version 2015.3.1214, it will be also available in the 2016 Q1 Release.

Calling the LogicalTreeHelper.GetChildren() does not include the DocumentHost and its contents.
Available in LIB version 2015.3.1214, it will be also available in the 2016 Q1 Release.

When the DropDownDisplayMode of the RadPaneGroup is set to Visible and that group is placed inside the DocumentHost calling the RemoveFromParent from a button places in the HeaderTemplate of the RadPane causes that RadPane instance to not be removed from the memory.

Available in LIB version 2016.3.1107, it will be also available in the 2017 R1 release.

Possible workaround:

A custom RadDocking control can be created, in which the OnCreateAutomationPeer() method is overridden. OnCreateAutomationPeer() should return a custom RadDocking AutomationPeer, in which the ToolWindowAutomationPeer is removed from the collection of child elements of RadDocking AutomationPeer.
Approach demonstrated in the attached project.

    After starting the application, there are 2+ RadPane instances
    Each RadPane contains multiple TextBox controls
    Click on a TextBox in first RadPane
    Switch to the next RadPane
    go back to the first RadPane

The desired behavior is that the focus is restored to the focused element in step 3. Currently no element is focused. The same scenario in RadTabControl is a bit different and the TabControl focused the first element in its TabItem content.

Available in LIB version 2016.3.1107, it will be also available in the 2017 R1 release.

Is there any option to create a connection line as a blank rectangle. At present I can see only solid lines only. Please see the attached image, and suggest how to get top two connection types.

Decline reason: The diagram exposes an API that allows you to create custom geometry for the connection. You can override the CreateGeometry(), CreateSourceCapGeometry() and CreateTargetCapGeometry() methods of RadDiagramConnection and create custom geometries. See the CustomConnectionCap SDK example: https://github.com/telerik/xaml-sdk/tree/master/Diagram/CustomConnectionCaps

Got this weird behavior with RadDocking with multiple monitors.

http://www.youtube.com/watch?v=8DDX5OiYRyM

As you could see the pane is being opened on the wrong side.

This happens only when the application is fully maximized, if its resized then this problem does not occur.

I am not able to reproduce this with a simple example. But you could contact me I can help in investigation.