Description of the problem
I support the deployed WPF ClickOnce application. The app has a feature that reports exceptions to me via email. After each deployment, I usually get one or two exception reports, as shown below. Less than 100 users.
The call stacks are not identical. It always says, “Failed to load the file or assembly,” and then displays a DLL, such as EntityFramework or Unity. It also says: "(Exception from HRESULT: 0x80070020)"
I have disabled ClickOnce automatic updates. I handle updates using the ApplicationDeployment API. After the update has been downloaded, I display the status message “Restart to start the latest version”. Then the user restarts the application. After restarting the application, "access to the file is excluded because it is being used by another process." Typically, if the user restarts the application again, the exception no longer occurs.
Another developer described a similar experience here .
What causes this?
At first I thought that maybe the previous version of the application was still closing when the user started the new version. However, the application is a single instance application. The single instance function is implemented in Main () long before this exception is thrown. This makes me pretty sure that this is not caused by two instances of my application. Also, my application does not directly read the EntityFramework or Unity DLLs.
I have two remaining hypotheses.
- The anti-virus scanner blocks the DLLs that just copied ClickOnce.
- There is a Microsoft bug in the ClickOnce update engine.
My question is: "Does anyone know what causes this?"
Call Stack Example # 1
Here is one example:
System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Practices.Unity, Version=2.1.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020) at MyNamespace.AppState.RestartTemplateCacheThread(UserOptions userOptions) at MyNamespace.AppState.RestartTemplateCacheThread() at MyNamespace.MainWindow.hyperlinkReconnect(Object sender, RoutedEventArgs e) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.ContentElement.RaiseEvent(RoutedEventArgs e) at System.Windows.Documents.Hyperlink.OnClick() at System.Windows.Documents.Hyperlink.DispatchNavigation(Object sender) at System.Windows.Documents.Hyperlink.DoUserInitiatedNavigation(Object sender) at System.Windows.Documents.Hyperlink.OnMouseLeftButtonUp(Object sender, MouseButtonEventArgs e) at System.Windows.Documents.Hyperlink.OnMouseLeftButtonUp(MouseButtonEventArgs e) at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e) at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent) at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e) at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.ContentElement.RaiseTrustedEvent(RoutedEventArgs args) at System.Windows.Input.InputManager.ProcessStagingArea() at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input) at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport) at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel) at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at System.Windows.Interop.HwndSource.InputFilterMessage(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 MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
String in RestartTemplateCacheThread (...) ...
var ioc = new UnityContainer().LoadConfiguration();
... which is supposedly the first Unity DLL output.
Call Stack Example # 2
In this example, the Unity DLL successfully loaded, but the EntityFramework DLL is locked.
System.IO.FileLoadException: Could not load file or assembly 'EntityFramework, Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020) at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type) at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName) at System.RuntimeType.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) at System.Type.GetType(String typeName) at Microsoft.Practices.Unity.Configuration.ConfigurationHelpers.TypeResolverImpl.ResolveAlias(String typeNameOrAlias) at Microsoft.Practices.Unity.Configuration.ConfigurationHelpers.TypeResolverImpl.ResolveTypeInternal(String typeNameOrAlias) at Microsoft.Practices.Unity.Configuration.ConfigurationHelpers.TypeResolverImpl.ResolveType(String typeNameOrAlias, Boolean throwIfResolveFails) at Microsoft.Practices.Unity.Configuration.RegisterElement.GetMappedType() at Microsoft.Practices.Unity.Configuration.RegisterElement.ConfigureContainer(IUnityContainer container) at Microsoft.Practices.Unity.Configuration.ContainerElement.<>c__DisplayClass1.<ConfigureContainer>b__0(ContainerConfiguringElement element) at Microsoft.Practices.ObjectBuilder2.EnumerableExtensions.ForEach[TItem](IEnumerable`1 sequence, Action`1 action) at Microsoft.Practices.Unity.Configuration.ContainerElement.ConfigureContainer(IUnityContainer container) at Microsoft.Practices.Unity.Configuration.UnityConfigurationSection.Configure(IUnityContainer container, String configuredContainerName) at Microsoft.Practices.Unity.Configuration.UnityContainerExtensions.LoadConfiguration(IUnityContainer container, UnityConfigurationSection section, String containerName) at Microsoft.Practices.Unity.Configuration.UnityContainerExtensions.LoadConfiguration(IUnityContainer container) at MyNamespace.AppState.RestartTemplateCacheThread(UserOptions userOptions) at MyNamespace.AppState.SetUserOptions(UserOptions options, Boolean restartBackgroundThreads) at MyNamespace.Models.DatasetManager.LoadDataset(String path) at MyNamespace.MainWindow.MainWindow_Loaded(Object sender, RoutedEventArgs args) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e) at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent) at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root) at MS.Internal.LoadedOrUnloadedOperation.DoWork() at System.Windows.Media.MediaContext.FireLoadedPendingCallbacks() at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks() at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) at System.Windows.Media.MediaContext.AnimatedRenderMessageHandler(Object resizedCompositionTarget) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)