Application Crash issue in WPF application in MVVM architecture - wpf

Question

Recently, we are facing crash issue's in our application(Not on regular basis, generally on the client side) and we are not able to track the reason for the error. Most of the time the error that we get from the log is something like this ..
Type : System.IndexOutOfRangeException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Message : Index was outside the bounds of the array.
Source : mscorlib
Help link :
Data : System.Collections.ListDictionaryInternal
TargetSite : Void Add(T)
HResult : -2146233080
Stack Trace : at System.Collections.Generic.List`1.Add(T item)
System.ComponentModel.BackgroundWorker.OnRunWorkerCompleted(RunWorkerCompletedEventArgs e)
at System.ComponentModel.BackgroundWorker.AsyncOperationCompleted(Object arg)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
Also in order to handle the crash at the application level, we have written certain code in App.xaml.cs file i.e.
private void CurrentDomain_UnhandledException(object sender,
UnhandledExceptionEventArgs e)
{
try
{
var exception = (Exception) e.ExceptionObject;
ExceptionHandler.HandleException(exception);
WpfMessageBox.Show(LocalizationManager.GetValue("AppErrorUnhandledException").ToString(),
LocalizationManager.GetValue("AppErrorUnhandledException").ToString(),
WpfMessageBoxButtons.OK,
WpfMessageBoxIcon.Error);
}
Is there anything we need to do besides this in order to stop the application to crash suddenly?
Note: Our application is based on MVVM pattern, concept such as service facade, unity, service orchestration, MutiThreading(Use of Background for calling service async)
P.S: Normally as per the logs, we are getting this error while caching the data.

Answer 1

Your CurrentDomain_UnhandledException will handle exceptions from Dispatcher, the UI thread.
BackgroundWorker is another thread, any exception occurs in this thread is not handled by the Dispatcher, and your system crashes.
You should handle the IndexOutOfRangeException inside the correct thread, the background one.
ng-HT