Win32Exception "Invalid window handle" thrown when IgnoreTaskbarOnMaximize bound to a true value

[Matthew-Heironimus]

If I create a MetroWindow and set its IgnoreTaskbarOnMaximize property to true in XAML, the window works the way I would expect (it covers the task bar when maximized).

<controls:MetroWindow  
    x:Class="FullScreenTest.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="http://metro.mahapps.com/winfx/xaml/controls"
    xmlns:fullScreenTest="clr-namespace:FullScreenTest"

    Height="350" Width="525" 

    Title="MainWindow" 
    WindowState="Maximized"
    IgnoreTaskbarOnMaximize="True"
    >
...

If I now bind the IgnoreTaskbarOnMaximize property to a property on my view model, the application will work correctly if the bound property is set to false. If, however, it is set to true, a "Invalid window handle" Win32Exception is thrown.

<controls:MetroWindow  
    x:Class="FullScreenTest.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="http://metro.mahapps.com/winfx/xaml/controls"
    xmlns:fullScreenTest="clr-namespace:FullScreenTest"

    Height="350" Width="525" 

    Title="MainWindow" 
    WindowState="Maximized"
    IgnoreTaskbarOnMaximize="{Binding FullScreenMode}"
    >
...

System.ComponentModel.Win32Exception was unhandled
  HResult=-2147467259
  Message=Invalid window handle
  Source=MahApps.Metro
  ErrorCode=-2147467259
  NativeErrorCode=1400
  StackTrace:
       at Standard.NativeMethods.GetWindowLongPtr(IntPtr hwnd, GWL nIndex)
       at MahApps.Metro.Behaviours.BorderlessWindowBehavior._ModifyStyle(WS removeStyle, WS addStyle)
       at MahApps.Metro.Behaviours.BorderlessWindowBehavior.IgnoreTaskbarOnMaximizePropertyChangedCallback(Object sender, EventArgs e)
       at MS.Internal.ComponentModel.PropertyChangeTracker.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
       at System.Windows.DependentList.InvalidateDependents(DependencyObject source, DependencyPropertyChangedEventArgs sourceArgs)
       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.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
       at System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)
       at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)
       at System.Windows.Data.BindingExpression.Activate(Object item)
       at System.Windows.Data.BindingExpression.AttachToContext(AttachAttempt attempt)
       at System.Windows.Data.BindingExpression.MS.Internal.Data.IDataBindEngineClient.AttachToContext(Boolean lastChance)
       at MS.Internal.Data.DataBindEngine.Task.Run(Boolean lastChance)
       at MS.Internal.Data.DataBindEngine.Run(Object arg)
       at MS.Internal.Data.DataBindEngine.OnLayoutUpdated(Object sender, EventArgs e)
       at System.Windows.ContextLayoutManager.fireLayoutUpdateEvent()
       at System.Windows.ContextLayoutManager.UpdateLayout()
       at System.Windows.UIElement.UpdateLayout()
       at System.Windows.Interop.HwndSource.SetLayoutSize()
       at System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)
       at System.Windows.Interop.HwndSource.set_RootVisual(Visual value)
       at System.Windows.Window.SetRootVisual()
       at System.Windows.Window.SetRootVisualAndUpdateSTC()
       at System.Windows.Window.SetupInitialState(Double requestedTop, Double requestedLeft, Double requestedWidth, Double requestedHeight)
       at System.Windows.Window.CreateSourceWindow(Boolean duringShow)
       at System.Windows.Window.CreateSourceWindowDuringShow()
       at System.Windows.Window.SafeCreateWindowDuringShow()
       at System.Windows.Window.ShowHelper(Object booleanBox)
       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.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 MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, 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.Threading.Dispatcher.Run()
       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 FullScreenTest.App.Main() in c:\Users\MCH0708\Documents\Visual Studio 2013\Projects\FullScreenTest\obj\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: