Error finding resources when the application is without focus for a period of time

## Describe the bug

When the application is open and no interaction is done for several minutes (without focus), an error occurs: "Cannot find resource named 'MahApps.Colors.Highlight'".

Stacktrace:

`[14:57:34 FTL 1 MyApplication.App] An unhandled exception has occurred
System.Windows.Markup.XamlParseException: 'Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.' Line number '39' and line position '91'.
---> System.Exception: Cannot find resource named 'MahApps.Colors.Highlight'. Resource names are case sensitive.
at System.Windows.StaticResourceExtension.ProvideValueInternal(IServiceProvider serviceProvider, Boolean allowDeferredReference)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
--- End of inner exception stack trace ---
at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
at System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.DeferredResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.DeferredAppResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.DependencyObject.GetEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, RequestFlags requests)
at System.Windows.DependencyObject.GetValueEntry(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, RequestFlags requests)
at System.Windows.DependencyObject.GetValue(DependencyProperty dp)
at System.Windows.StyleHelper.GetChildValueHelper(UncommonField`1 dataField, ItemStructList`1& valueLookupList, DependencyProperty dp, DependencyObject container, FrameworkObject child, Int32 childIndex, Boolean styleLookup, EffectiveValueEntry& entry, ValueLookupType& sourceType, FrameworkElementFactory templateRoot)
at System.Windows.StyleHelper.GetChildValue(UncommonField`1 dataField, DependencyObject container, Int32 childIndex, FrameworkObject child, DependencyProperty dp, FrugalStructList`1& childRecordFromChildIndex, EffectiveValueEntry& entry, ValueLookupType& sourceType, FrameworkElementFactory templateRoot)
at System.Windows.StyleHelper.GetValueFromTemplatedParent(DependencyObject container, Int32 childIndex, FrameworkObject child, DependencyProperty dp, FrugalStructList`1& childRecordFromChildIndex, FrameworkElementFactory templateRoot, EffectiveValueEntry& entry)
at System.Windows.FrameworkElement.GetValueFromTemplatedParent(DependencyProperty dp, EffectiveValueEntry& entry)
at System.Windows.FrameworkElement.GetRawValue(DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry& entry)
at System.Windows.FrameworkElement.EvaluateBaseValueCore(DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry& newEntry)
at System.Windows.DependencyObject.EvaluateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry newEntry, OperationType operationType)
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.StyleHelper.InvalidateDependents(Style ownerStyle, FrameworkTemplate frameworkTemplate, DependencyObject container, DependencyProperty dp, FrugalStructList`1& dependents, Boolean invalidateOnlyContainer)
at System.Windows.StyleHelper.OnTriggerSourcePropertyInvalidated(Style ownerStyle, FrameworkTemplate frameworkTemplate, DependencyObject container, DependencyProperty dp, DependencyPropertyChangedEventArgs changedArgs, Boolean invalidateOnlyContainer, FrugalStructList`1& triggerSourceRecordFromChildIndex, FrugalMap& propertyTriggersWithActions, Int32 sourceChildIndex)
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.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
at System.Windows.ResourceReferenceExpression.InvalidateExpressionValue(Object sender, EventArgs e)
at System.Windows.TreeWalkHelper.InvalidateResourceReferences(DependencyObject d, ResourcesChangeInfo info)
at System.Windows.TreeWalkHelper.OnResourcesChanged(DependencyObject d, ResourcesChangeInfo info, Boolean raiseResourceChangedEvent)
at System.Windows.TreeWalkHelper.OnResourcesChangedCallback(DependencyObject d, ResourcesChangeInfo info, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(FrameworkElement fe, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.VisitNode(DependencyObject d, Boolean visitedViaVisualTree)
at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
at System.Windows.DescendentsWalker`1.StartWalk(DependencyObject startNode, Boolean skipStartNode)
at System.Windows.TreeWalkHelper.InvalidateOnResourcesChange(FrameworkElement fe, FrameworkContentElement fce, ResourcesChangeInfo info)
at System.Windows.Application.InvalidateResourceReferenceOnWindowCollection(WindowCollection wc, ResourcesChangeInfo info)
at System.Windows.ResourceDictionary.NotifyOwners(ResourcesChangeInfo info)
at System.Windows.ResourceDictionary.EndInit()
at ControlzEx.Theming.ThemeManager.ChangeTheme(Object target, ResourceDictionary resourceDictionary, Theme oldTheme, Theme newTheme)
at ControlzEx.Theming.ThemeManager.ChangeTheme(Object target, ResourceDictionary resourceDictionary, Theme newTheme)
at ControlzEx.Theming.ThemeManager.ChangeTheme(Application app, Theme newTheme)
at ControlzEx.Theming.ThemeManager.SyncTheme(Nullable`1 syncMode)
at ControlzEx.Theming.ThemeManager.b__72_0()
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)
[14:57:34 FTL 1 MyApplication.App] An unhandled exception has occurred
System.Windows.Markup.XamlParseException: 'Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.' Line number '33' and line position '20'.
---> System.Exception: Cannot find resource named 'MahApps.Colors.ThemeForeground'. Resource names are case sensitive.
at System.Windows.StaticResourceExtension.ProvideValueInternal(IServiceProvider serviceProvider, Boolean allowDeferredReference)
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
--- End of inner exception stack trace ---
at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.ResourceDictionary.CreateObject(KeyRecord key)
at System.Windows.ResourceDictionary.OnGettingValue(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.OnGettingValuePrivate(Object key, Object& value, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValueWithoutLock(Object key, Boolean& canCache)
at System.Windows.ResourceDictionary.GetValue(Object key, Boolean& canCache)
at System.Windows.DeferredResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.DeferredAppResourceReference.GetValue(BaseValueSourceInternal valueSource)
at System.Windows.DependencyObject.GetEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, RequestFlags requests)
at System.Windows.DependencyObject.GetValueEntry(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, RequestFlags requests)
at System.Windows.DependencyObject.GetValue(DependencyProperty dp)
at MS.Internal.Text.TextProperties.InitCommon(DependencyObject target)
at MS.Internal.Text.TextProperties..ctor(FrameworkElement target, Boolean isTypographyDefaultValue)
at System.Windows.Controls.TextBlock.GetLineProperties()
at System.Windows.Controls.TextBlock.EnsureTextBlockCache()
at System.Windows.Controls.TextBlock.OnRender(DrawingContext ctx)
at System.Windows.UIElement.Arrange(Rect finalRect)
at MS.Internal.Helper.ArrangeElementWithSingleChild(UIElement element, Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Border.ArrangeOverride(Size finalSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Primitives.TabPanel.ArrangeHorizontal(Size arrangeSize)
at System.Windows.Controls.Primitives.TabPanel.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at MS.Internal.Helper.ArrangeElementWithSingleChild(UIElement element, Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Border.ArrangeOverride(Size finalSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at MS.Internal.Helper.ArrangeElementWithSingleChild(UIElement element, Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Border.ArrangeOverride(Size finalSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at MS.Internal.Helper.ArrangeElementWithSingleChild(UIElement element, Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Grid.ArrangeOverride(Size arrangeSize)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.Controls.Control.ArrangeOverride(Size arrangeBounds)
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
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.Media.MediaContext.Resize(ICompositionTarget resizedCompositionTarget)
at System.Windows.Interop.HwndTarget.OnResize()
at System.Windows.Interop.HwndTarget.HandleMessage(WindowMessage msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Interop.HwndSource.HwndTargetFilterMessage(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)
Exception thrown: 'System.Windows.Markup.XamlParseException' in PresentationFramework.dll
'Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.' Line number '29' and line position '20'.
`

## Steps to reproduce
1. Leave the application open without focus for a good time (in my machine is about 25 minutes).
2. See error

## Environment

```
MahApps.Metro version: v2.4.7
Windows build number: Win10 1909 [Version 18363.1556]
Visual Studio: 2019 16.6.0
Target Framework: .Net 5
```

Start by reproducing the failure after leaving the WPF application unfocused for several minutes, then trace the XAML resource lookup for MahApps.Colors.Highlight using the provided stack trace. Done means the application no longer throws the XamlParseException or reports the missing resource after the idle, unfocused period.

Written by the indexing model from the issue text.