UnobservedTaskException-任务来自何处

在我的MVC应用程序中，我有时会遇到一个异常，比如：

System.Net.WebException: The request was aborted: The request was canceled.
   at System.Net.HttpWebRequest.BeginGetRequestStream(AsyncCallback callback, Object state)
   at System.Net.Http.HttpClientHandler.StartGettingRequestStream(RequestState state)
   at System.Net.Http.HttpClientHandler.<>c__DisplayClass4.<PrepareAndStartContentUpload>b__0(Task task)
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---

编辑这是我看到的另一种：

System.Exception: Unhandled Task Error ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Web.HttpApplication.PipelineStepManager.ResumeSteps(Exception error)
   at System.Web.HttpApplication.ResumeStepsFromThreadPoolThread(Exception error)
   at System.Web.HttpApplication.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar)
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---

这是我在事件日志中看到的内容，但它在时间或计数上并不完全相关。

A fatal alert was generated and sent to the remote endpoint. This may result in termination of the connection. The TLS protocol defined fatal error code is 40. The Windows SChannel error state is 1205.
An TLS 1.2 connection request was received from a remote client application, but none of the cipher suites supported by the client application are supported by the server. The SSL connection request has failed.

/编辑

是否有方法识别异常的来源/位置，或获取有关异常来源的任何其他信息？

编辑2这是我看到的另一个。它们都与OnAsyncHandlerComplete有关，但我不确定来源是什么

System.Exception: Unhandled Task Error ---> System.NullReferenceException: Object reference not set to an instance of an object.
at System.Web.HttpApplication.get_CurrentModuleContainer()
at System.Web.HttpApplication.PipelineStepManager.ResumeSteps(Exception error)
at System.Web.HttpApplication.ResumeStepsFromThreadPoolThread(Exception error)
at System.Web.HttpApplication.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar)
at System.Threading.Tasks.Task.Execute()
--- End of inner exception stack trace ---

/编辑2