Assembly: System.Net (in System.Net.dll)
asyncResult is null.
The request did not complete, and no stream is available.
asyncResult was not returned by the current instance from a call to BeginGetRequestStream.
This method was called previously using asyncResult.
This method is not implemented.
Abort was previously called.
An error occurred while processing the request.
The method completes an asynchronous request for a stream that was started by the BeginGetRequestStream method. After the Stream object has been returned, you can send data with the HttpWebRequest by using the Stream.Write method.
You must call the Stream.Close method to close the stream and release the connection for reuse. Failure to close the stream causes your application to run out of connections.