Data error's using TransitionPresenter

When using the TransitionPresenter I'm getting errors in my output window: 

System.Windows.Data Error: 25 : Both 'ContentTemplate' and 'ContentTemplateSelector' are set;  'ContentTemplateSelector' will be ignored. ContentPresenter:'ContentPresenter' (Name='')

 I don't set the ContentTemplateSelector, so I'm not sure why this is happening. Here is my xaml:

 <shared:TransitionPresenter Grid.Column="0"
                                        IsEnabled="{Binding HasValidEntity}"
                                        IsFirstContentTransitionEnabled="True"
                                        Content="{Binding ActiveItem}"
                                        ContentTemplate="{DynamicResource HeaderedContentControlItemTemplate}"
                                        DefaultDuration="0:0:1">
                <shared:TransitionPresenter.Transition>
                    <shared:FourBoxWipeTransition />
                </shared:TransitionPresenter.Transition>
            </shared:TransitionPresenter>