dotnet/wpf · error · InvalidOperationException

SR.ShutdownModeWhenAppShutdown

Error message

SR.ShutdownModeWhenAppShutdown

What it means

ShutdownMode cannot be changed once the application has begun shutting down or is fully shut down. The setter throws InvalidOperationException(SR.ShutdownModeWhenAppShutdown) when IsShuttingDown or _appIsShutdown is true. This protects the shutdown sequence from contradictory configuration mid-flight.

Solutions

  1. Set ShutdownMode during application startup, before Run() is invoked
  2. Guard the assignment with Application.Current.Dispatcher.HasShutdownStarted checks
  3. Move the setting out of Exit/Closed handlers into App constructor or OnStartup
  4. If the app already shut down, create a new Application instance instead of reconfiguring the old one

Example fix

// before
protected override void OnExit(ExitEventArgs e)
{
    Current.ShutdownMode = ShutdownMode.OnExplicitShutdown; // throws
}
// after
public App()
{
    ShutdownMode = ShutdownMode.OnExplicitShutdown;
}
Defensive patterns

Strategy: type-guard

Validate before calling

bool canSetMode() => Application.Current != null && !Application.Current.Dispatcher.HasShutdownStarted;

Type guard

bool ShutdownPending(Application app) => app.Dispatcher.HasShutdownStarted;

Try / catch

try { app.ShutdownMode = mode; } catch (InvalidOperationException) { /* app is shutting down; skip */ }

Prevention

When it happens

Trigger: Assigning Application.ShutdownMode from within the Exit event handler, after Shutdown() has been called, inside a Window.Closed handler during app teardown, or on a restarted-but-disposed Application instance.

Common situations: Cleanup code in OnExit trying to force OnExplicitShutdown; re-running logic after Application.Run returned; event handlers fired during shutdown cascades.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/ea628c28f99a64fd. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Application.cs:840

        /// </summary>
        public ShutdownMode ShutdownMode
        {
            get
            {
                VerifyAccess();
                return _shutdownMode;
            }

            set
            {
                VerifyAccess();
                if ( !IsValidShutdownMode(value) )
                {
                    throw new InvalidEnumArgumentException("value", (int)value, typeof(ShutdownMode));
                }
                if (IsShuttingDown || _appIsShutdown)
                {
                    throw new InvalidOperationException(SR.ShutdownModeWhenAppShutdown);
                }

                _shutdownMode = value;
            }
        }

        /// <summary>
        ///     Current locally defined Resources
        /// </summary>
        [Ambient]
        public ResourceDictionary Resources
        {
            //Don't use  VerifyAccess() here since Resources can be set from any thread.
            //We synchronize access using _globalLock

            get
            {
                ResourceDictionary resources;

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