[BUG] the 1.2 crash when loading plan from query store

[rferraton]

Component

Desktop App (Windows)

SQL Performance Studio Version

1.2

Operating System

Windows

Describe the Bug

Fetch query from querystore, try to load the plan ==> app crash

Steps to Reproduce

Fetch query from querystore, try to load the plan ==> app crash

Expected Behavior

Fetch query from querystore, try to load the plan ==> plan load

Actual Behavior

Fetch query from querystore, try to load the plan ==> app crash

Plan File

No response

Screenshots

No response

[rferraton]

Fix proposition

in QuerySessionControl.axaml.cs replace the current SetStatus code by this one

    private void SetStatus(string text, bool autoClear = true)
    {
        _statusClearCts?.Cancel();
        _statusClearCts?.Dispose();
        _statusClearCts = null; // ← prevent stale reference to a disposed CTS

        StatusText.Text = text;

        if (autoClear && !string.IsNullOrEmpty(text))
        {
            _statusClearCts = new CancellationTokenSource();
            var token = _statusClearCts.Token;
            _ = Task.Delay(3000, token).ContinueWith(_ =>
            {
                Avalonia.Threading.Dispatcher.UIThread.Post(() =>
                {
                    StatusText.Text = "";
                    _statusClearCts = null; // ← also clear after natural expiry
                });
            }, TaskContinuationOptions.OnlyOnRanToCompletion);

        }
    }

[erikdarlingdata]

Thanks for reporting this. Could you provide more detail so we can track down the actual crash?

1. Stack trace or crash log — Check %LOCALAPPDATA%\PerformanceMonitor\Logs\ or the Windows Event Viewer (Application log) for the exception details
2. Which button did you click? — "Load Selected Plans" in the toolbar, or right-click → "Load Plan" on a specific row?
3. What database/server were you connected to? (SQL Server version, on-prem vs Azure)
4. Does it crash on every query, or only specific ones?

The SetStatus fix you suggested is good CTS hygiene but wouldn't cause a crash during plan loading — that code path goes through OnQueryStorePlansSelected → AddPlanTab → PlanViewerControl.LoadPlan, which is separate from the status text timer. The crash is more likely in the plan XML parsing or rendering. A stack trace would tell us exactly where.

[rferraton]

1 - Stack Trace from WEV :

Application: PlanViewer.App.exe
CoreCLR Version: 8.0.2325.60607
.NET Version: 8.0.23
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.ObjectDisposedException: The CancellationTokenSource has been disposed.
   at System.Threading.CancellationTokenSource.Cancel()
   at PlanViewer.App.Controls.QuerySessionControl.SetStatus(String text, Boolean autoClear) in D:\a\PerformanceStudio\PerformanceStudio\src\PlanViewer.App\Controls\QuerySessionControl.axaml.cs:line 324
   at PlanViewer.App.Controls.QuerySessionControl.OnQueryStorePlansSelected(Object sender, List`1 plans) in D:\a\PerformanceStudio\PerformanceStudio\src\PlanViewer.App\Controls\QuerySessionControl.axaml.cs:line 1062
   at PlanViewer.App.Controls.QueryStoreGridControl.LoadSelected_Click(Object sender, RoutedEventArgs e) in D:\a\PerformanceStudio\PerformanceStudio\src\PlanViewer.App\Controls\QueryStoreGridControl.axaml.cs:line 214
   at InvokeStub_EventHandler`1.Invoke(Object, Span`1)
   at System.Reflection.MethodBaseInvoker.InvokeWithFewArgs(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   --- End of inner exception stack trace ---
   at System.Reflection.MethodBaseInvoker.InvokeWithFewArgs(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Delegate.DynamicInvokeImpl(Object[] args)
   at Avalonia.Interactivity.EventRoute.RaiseEventImpl(RoutedEventArgs e)
   at Avalonia.Interactivity.EventRoute.RaiseEvent(Interactive source, RoutedEventArgs e)
   at Avalonia.Interactivity.Interactive.RaiseEvent(RoutedEventArgs e)
   at Avalonia.Controls.Button.OnClick()
   at Avalonia.Controls.Button.OnPointerReleased(PointerReleasedEventArgs e)
   at Avalonia.Input.InputElement.<>c.<.cctor>b__33_9(InputElement x, PointerReleasedEventArgs e)
   at Avalonia.Reactive.LightweightObservableBase`1.PublishNext(T value)
   at Avalonia.Interactivity.EventRoute.RaiseEventImpl(RoutedEventArgs e)
   at Avalonia.Interactivity.EventRoute.RaiseEvent(Interactive source, RoutedEventArgs e)
   at Avalonia.Interactivity.Interactive.RaiseEvent(RoutedEventArgs e)
   at Avalonia.Input.MouseDevice.MouseUp(IMouseDevice device, UInt64 timestamp, IInputRoot root, Point p, PointerPointProperties props, KeyModifiers inputModifiers, IInputElement hitTest)
   at Avalonia.Input.MouseDevice.ProcessRawEvent(RawPointerEventArgs e)
   at Avalonia.Controls.TopLevel.<>c.<HandleInput>b__150_0(Object state)
   at Avalonia.Threading.Dispatcher.Send(SendOrPostCallback action, Object arg, Nullable`1 priority)
   at Avalonia.Controls.TopLevel.HandleInput(RawInputEventArgs e)
   at Avalonia.Win32.WindowImpl.AppWndProc(IntPtr hWnd, UInt32 msg, IntPtr wParam, IntPtr lParam)
   at Avalonia.Win32.WindowImpl.WndProcMessageHandler(IntPtr hWnd, UInt32 msg, IntPtr wParam, IntPtr lParam)
   at Avalonia.Win32.Interop.UnmanagedMethods.DispatchMessage(MSG& lpmsg)
   at Avalonia.Win32.Win32DispatcherImpl.RunLoop(CancellationToken cancellationToken)
   at Avalonia.Threading.DispatcherFrame.Run(IControlledDispatcherImpl impl)
   at Avalonia.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at Avalonia.Threading.Dispatcher.MainLoop(CancellationToken cancellationToken)
   at Avalonia.Controls.ApplicationLifetimes.ClassicDesktopStyleApplicationLifetime.StartCore(String[] args)
   at Avalonia.Controls.ApplicationLifetimes.ClassicDesktopStyleApplicationLifetime.Start(String[] args)
   at Avalonia.ClassicDesktopStyleApplicationLifetimeExtensions.StartWithClassicDesktopLifetime(AppBuilder builder, String[] args, Action`1 lifetimeBuilder)
   at PlanViewer.App.Program.Main(String[] args) in D:\a\PerformanceStudio\PerformanceStudio\src\PlanViewer.App\Program.cs:line 21

and

Nom de l'application défaillante : PlanViewer.App.exe, version : 1.2.0.0, horodatage : 0x69340000
Nom du module défaillant : KERNELBASE.dll, version : 10.0.26100.7920, horodatage : 0x0cc2a083
Exception code: 0xe0434352
Fault offset: 0x00000000000c73fa
Identifiant du processus défaillant : 0xB594
Heure de début de l'application défaillante : 0x1DCB6B45D9B0187
Chemin de l'application défaillante : D:\sources\PerformanceStudio-win-x64_1-2\PlanViewer.App.exe
Chemin du module défaillant : C:\WINDOWS\System32\KERNELBASE.dll
ID du rapport : 48a6ff3f-8b8a-4940-b57e-85984ea73aaf
Nom complet du package défaillant : 
Package défaillant – ID d'application relatif : 

2 - Button :
Yes "Load Plan" but also "QueryStore" button after switching databases

3 - Database Version
2022, 2025 on prem

4 - Does it crash on every query : Yes any query

[frodr1k]

I can add some information here aswell. I have the same issue .

Win11

I left klick on a row and open query plan, and it just exits.

Against 2022, 2025, both gigantic (afaik) and small plans.

[erikdarlingdata]

Fixed in v1.2.0 — thanks for the detailed stack trace and the fix in #106, @rferraton! You were right that the root cause was the CTS disposal racing with the Task.Delay continuation. We incorporated your approach (null-first before Cancel/Dispose) in #107.

The updated v1.2.0 release is live with the fix: https://github.com/erikdarlingdata/PerformanceStudio/releases/tag/v1.2.0