crash

### Microsoft PowerToys version

0.91.1.0

### Installation method

Microsoft Store

### Area(s) with issue?

General

### Steps to reproduce

normal working on windows and firefox nothing special

### ✔️ Expected Behavior

Version: 0.91.1.0
OS Version: Microsoft Windows NT 10.0.26200.0
IntPtr Length: 8
x64: True
Date: 28.07.2026 11:58:05
Exception:
System.Runtime.InteropServices.COMException (0x80263001): {Die Desktopkomposition ist deaktiviert.} Der Vorgang konnte nicht abgeschlossen werden, da die Desktopkomposition deaktiviert ist. (0x80263001)
at Standard.NativeMethods.DwmExtendFrameIntoClientArea(IntPtr hwnd, MARGINS& pMarInset)
at System.Windows.Appearance.WindowBackdropManager.UpdateGlassFrame(IntPtr hwnd, WindowBackdropType backdropType)
at System.Windows.Appearance.WindowBackdropManager.ApplyBackdrop(IntPtr hwnd, WindowBackdropType backdropType)
at System.Windows.Appearance.WindowBackdropManager.SetBackdrop(Window window, WindowBackdropType backdropType)
at System.Windows.ThemeManager.ApplyStyleOnWindow(Window window, Boolean useLightColors)
at System.Windows.ThemeManager.OnSystemThemeChanged()
at System.Windows.SystemResources.SystemThemeFilterMessage(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)

### ❌ Actual Behavior

_No response_

### Upload Bug Report ZIP-file

[2026-07-28.txt](https://github.com/user-attachments/files/30457178/2026-07-28.txt)

### Additional Information

Windows 11 25H2 (Build 26200.8875)
C:\Users\Muk>dotnet --list-runtimes
Microsoft.AspNetCore.App 8.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 10.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 10.0.7 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

.Graphics Driver: NVIDIA 32.0.16.1074 Date 02.07.2026

System Language: German

### Other Software

Firefox

Reproduce the crash on Windows 11 25H2 with PowerToys 0.91.1.0 and inspect the reported path from SystemResources.SystemThemeFilterMessage through ThemeManager and WindowBackdropManager.UpdateGlassFrame to Standard.NativeMethods.DwmExtendFrameIntoClientArea. Determine why the desktop-composition error is unhandled; done means the reported theme-change scenario no longer crashes.

Written by the indexing model from the issue text.