ActiproSoftware WPF applincation error?

I am getting this:

System.ComponentModel.LicenseException was unhandled
HResult=-2146232063
Message=An instance of type 'ActiproSoftware.Products.Docking.DockingLicenseToken' was being created, and a valid license could not be granted for the type 'ActiproSoftware.Products.Docking.DockingLicenseToken'. Please, contact the manufacturer of the component for more information.
Source=System
StackTrace:
at System.ComponentModel.LicenseManager.Validate(Type type, Object instance)
at ActiproSoftware.Products.Docking.DockingLicenseToken..ctor(Object owner)
at ActiproSoftware.Windows.Controls.Docking.DockSite.OnLoaded(Object sender, RoutedEventArgs e)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
at MS.Internal.LoadedOrUnloadedOperation.DoWork()
at System.Windows.Media.MediaContext.FireLoadedPendingCallbacks()
at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
at System.Windows.Application.RunDispatcher(Object ignore)
at System.Windows.Application.RunInternal(Window window)
at System.Windows.Application.Run(Window window)
at System.Windows.Application.Run()
at obsessor.App.Main() in C:\myProjects\obsessor\obsessor\obj\x86\Debug\App.g.cs:line 0
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:

Please can you help me.

 also here is my xaml file:

<Window x:Class="obsessor.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:shared="http://schemas.actiprosoftware.com/winfx/xaml/shared" 
	xmlns:docking="http://schemas.actiprosoftware.com/winfx/xaml/docking" 
	xmlns:themes="http://schemas.actiprosoftware.com/winfx/xaml/themes" 
	Title="Nested Dock Sites QuickStart"	
	Width="800" Height="600"
    >

    <!-- Outer DockSite -->
    <docking:DockSite x:Name="outerDockSite">
        

        <docking:SplitContainer>
            <docking:Workspace>
                <docking:TabbedMdiHost>
                    <docking:TabbedMdiContainer>

                        <docking:DocumentWindow Title="Document1">
                            <!-- Inner DockSite 1 -->
                            <docking:DockSite x:Name="innerDockSite1" >
                                <docking:ToolWindowContainer>
                                    <docking:ToolWindow Title="Inner DockSite 1-1">
                                        <TextBox BorderThickness="0" />
                                    </docking:ToolWindow>
                                    <docking:ToolWindow Title="Inner DockSite 1-2">
                                        <TextBox BorderThickness="0" />
                                    </docking:ToolWindow>
                                </docking:ToolWindowContainer>
                            </docking:DockSite>
                        </docking:DocumentWindow>

                        <docking:DocumentWindow Title="Document2">
                            <!-- Inner DockSite 2 -->
                            <docking:DockSite x:Name="innerDockSite2"  >
                                <docking:SplitContainer>
                                    <docking:ToolWindowContainer>
                                        <docking:ToolWindow Title="Inner DockSite 2-1">
                                            <TextBox BorderThickness="0" />
                                        </docking:ToolWindow>
                                        <docking:ToolWindow Title="Inner DockSite 2-2">
                                            <TextBox BorderThickness="0" />
                                        </docking:ToolWindow>
                                    </docking:ToolWindowContainer>

                                    <docking:Workspace>
                                        <docking:TabbedMdiHost>
                                            <docking:TabbedMdiContainer>
                                                <docking:DocumentWindow Title="InnerDocument1">
                                                    <TextBox BorderThickness="0" />
                                                </docking:DocumentWindow>
                                                <docking:DocumentWindow Title="InnerDocument2">
                                                    <TextBox BorderThickness="0" />
                                                </docking:DocumentWindow>
                                            </docking:TabbedMdiContainer>
                                        </docking:TabbedMdiHost>
                                    </docking:Workspace>
                                </docking:SplitContainer>
                            </docking:DockSite>
                        </docking:DocumentWindow>

                    </docking:TabbedMdiContainer>
                </docking:TabbedMdiHost>
            </docking:Workspace>

            <docking:ToolWindowContainer>
                <docking:ToolWindow Title="Outer DockSite 1">
                    <TextBox BorderThickness="0" />
                </docking:ToolWindow>
                <docking:ToolWindow Title="Outer DockSite 2">
                    <TextBox BorderThickness="0" />
                </docking:ToolWindow>
            </docking:ToolWindowContainer>
        </docking:SplitContainer>
    </docking:DockSite>

</Window>

Simon