Error with Specified element is already the logical child ..

Question

Hello i have a problem i my application i get this error:
'Specified element is already the logical child of another element. Disconnect it first.'

I have tray to get more data of the error by catch it in try catch but i get only this info :

   at System.Windows.FrameworkElement.ChangeLogicalParent(DependencyObject newParent)     at System.Windows.FrameworkElement.AddLogicalChild(Object child)     at System.Windows.Controls.ContentControl.OnContentChanged(Object oldContent, Object newContent)     at System.Windows.Controls.ContentControl.OnContentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)     at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)     at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)     at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)     at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)     at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)     at System.Windows.Data.BindingOperations.SetBinding(DependencyObject target, DependencyProperty dp, BindingBase binding)     at System.Windows.Controls.PopupControlService.RaiseToolTipOpeningEvent()     at System.Windows.Controls.PopupControlService.OnRaiseToolTipOpeningEvent(Object sender, EventArgs e)     at System.Windows.Threading.DispatcherTimer.FireTick(Object unused)     at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)     at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)     at System.Windows.Threading.DispatcherOperation.InvokeImpl()     at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)     at System.Threading.ExecutionContext.runTryCode(Object userData)     at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)     at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)     at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)     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 MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)     at System.Windows.Threading.Dispatcher.InvokeImpl(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 Else.Detal.WPF.App.Main()


Maybe someone has some idea what the problem is ??

Gratings

Gregor