c# - 500 internal server error at GetResponse()

Question

I have a heavy traffic aspx page calling a web service upon every user`s request as follows.

string uri = "Path.asmx";
string soap = "soap xml string";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.Headers.Add("SOAPAction", ""http://xxxxxx"");
request.ContentType = "text/xml;charset="utf-8"";
request.Accept = "text/xml";
request.Method = "POST";

using (Stream stm = request.GetRequestStream())
{
    using (StreamWriter stmw = new StreamWriter(stm))
    {
        stmw.Write(soap);
    }
}
WebResponse response = request.GetResponse();
response.close();

Everything is working fine but sometimes I am getting the following error.

The remote server returned an error: (500) Internal Server Error. at System.Net.HttpWebRequest.GetResponse()

Does anybody have any idea about this error or can anybody tell me if I am doing wrong.

Answer 1

For me this error occurred because I had 2 web API actions that had the exact same signatures and both had the same verbs, HttpPost, what I did was change one of the verbs (the one used for updating) to PUT and the error was removed. The following in my catch statement helped in getting to the root of the problem:

catch (WebException webex)
{
                WebResponse errResp = webex.Response;
                using (Stream respStream = errResp.GetResponseStream())
                {
                    StreamReader reader = new StreamReader(respStream);
                    string text = reader.ReadToEnd();
                }
}