Hello,

1. I have a Control template in the resource of an XamDockManager:

The special is that the Header cotnains a header presenter and a label - with a string in the header the problem doesn't occur.

<igDock:XamDockManager  Name="DockManager">
                <igDock:XamDockManager.Resources>
                    <ControlTemplate x:Key="ContentPaneTemplate">
                        <igDock:ContentPane>
                            <igDock:ContentPane.Header>
                                <igDock:PaneHeaderPresenter>
                                    <Label>hello</Label>
                                </igDock:PaneHeaderPresenter>
                             </igDock:ContentPane.Header>
                            <TextBox Text="..."/>
                        </igDock:ContentPane>
                    </ControlTemplate>
                </igDock:XamDockManager.Resources>
                <igDock:DocumentContentHost>
                    <igDock:SplitPane Name="ContentSplitPane">
                        <igDock:TabGroupPane Name="ContentTabGroupPane">
                        </igDock:TabGroupPane>
                    </igDock:SplitPane>
                </igDock:DocumentContentHost>
            </igDock:XamDockManager>

2. I Load this template in the code behind:

    Private Function CreateContentPane() As ContentPane
        Return DirectCast(DirectCast(Me.DockManager.Resources.Item("ContentPaneTemplate"), ControlTemplate).LoadContent, ContentPane)
    End Function

3. I assign the content pane as content of a microsoft-wpf-control:

Me.TestButton.Content = CreateContentPane

4. TestCase 3. works. So i assume i didn't do something wrong. Also with a ms-tabcontrol it works. That's why i assume it is an bug in your implementation:

5. Now if i assign the aContent to the header of a IgDock.ContentPane:

Me.ContentTabGroupPane.Items.Add(Me.CreateContentPane)

6. For the first it works but later when the messagequeue is processed i receive an error that an element is allready child of another logical parent.

7. I receive the same error immediately when i try to set the aContentPane as SelecteItem of the TabPane:

Dim aContentPane As ContentPane = Me.CreateContentPane()

Me.ContentTabGroupPane.Items.Add(aContentPane)

Me.ContentTabGroupPane.SelectedItem = aContentPane ' error