BUG: Unable to cast object of type 'System.Windows.Media.Color' to type 'System.Windows.Expression'

[yozhic]

Checks

• I have checked that this issue has not already been reported.

• I am using the latest version of Flow Launcher.

• I am using the prerelease version of Flow Launcher.

Problem Description

This is a follow-up to report #4298 — the issue still persists.

So, the trick of replacing StaticResource with DynamicResource isn't working for me. I tried reversing the replacement (DynamicResource with StaticResource) — no effect. The error occurs with both values.

Take a look at the exception message

Flow Launcher version: 2.1.1
OS Version: 22631.5039
IntPtr Length: 8
x64: True

Python Path: c:\bin\python\python312\pythonw.exe
Node Path: c:\bin\nodejs\node.exe

Date: 04/18/2026 10:01:06
Exception:
System.InvalidCastException: Unable to cast object of type 'System.Windows.Media.Color' to type 'System.Windows.Expression'.
   at System.Windows.Freezable.CloneCoreCommon(Freezable sourceFreezable, Boolean useCurrentValue, Boolean cloneFrozenValues)
   at System.Windows.Freezable.Clone()
   at System.Windows.StyleHelper.GetInstanceValue(UncommonField`1 dataField, DependencyObject container, FrameworkElement feChild, FrameworkContentElement fceChild, Int32 childIndex, DependencyProperty dp, Int32 i, EffectiveValueEntry& entry)
   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.GetValueFromStyleOrTemplate(FrameworkObject fo, 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.StyleHelper.InvalidateContainerDependents(DependencyObject container, FrugalStructList`1& exclusionContainerDependents, FrugalStructList`1& oldContainerDependents, FrugalStructList`1& newContainerDependents)
   at System.Windows.StyleHelper.DoStyleInvalidations(FrameworkElement fe, FrameworkContentElement fce, Style oldStyle, Style newStyle)
   at System.Windows.FrameworkElement.OnStyleChanged(DependencyObject d, 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.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Flow.Launcher.MainWindow.InitProgressbarAnimation() in C:\projects\flow-launcher\Flow.Launcher\MainWindow.xaml.cs:line 1110
   at Flow.Launcher.MainWindow.ProgressBar_Loaded(Object sender, RoutedEventArgs e) in C:\projects\flow-launcher\Flow.Launcher\MainWindow.xaml.cs:line 356
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
   at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
   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 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)

To Reproduce

1. Switch the Windows theme from dark to light. I do this using the AutoDarkMode 11.0.0.54 utility (see screenshot below).
2. Call up FlowLauncher.
3. An error window appears.

Screenshots

Flow Launcher Version

2.1.1

Windows Build Number

10.0.22631.5039

Error Log

Flow.Launcher.2026-04-18.log