Strange object disposed exception on HttpWebResponse

Question

I am working on a program that automatically queries a website every 5 seconds. It has been working fine for the last few days, but today when I simply restarted it, it keeps throwing System.ObjectDisposedException on the line marked underneath. I should mention that accessing this URL via a browser on the same machine works fine.

Code:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://www.bitstamp.net/api/ticker/");

request.Method = "GET";

try
{
    // ObjectDisposedException thrown here
    using (HttpWebResponse response = (HttpWebResponse)request.GetResponse()) 
    {
        using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
        {
            string resultString = reader.ReadToEnd();
            return resultString;
        }
    }
}
catch (WebException ex)
{
    // Handle it
}

Stack Trace:

System.ObjectDisposedException occurred
    _HResult=-2146232798
   _message=Cannot access a disposed object.
    HResult=-2146232798
    IsTransient=false
    Message=Cannot access a disposed object.
Object name: 'SslStream'.
Source=System
    ObjectName=SslStream
StackTrace:
at System.Net.Security.SslState.ValidateCreateContext(Boolean isServer, String targetHost, SslProtocols enabledSslProtocols, X509Certificate serverCertificate, X509CertificateCollection clientCertificates, Boolean remoteCertRequired, Boolean checkCertRevocationStatus, Boolean checkCertName)
 InnerException:

Is there something I am doing wrong? I do not even access the response stream before the using, how can it be disposed?

EDIT: Added url and stack trace

What happens if you visit the URL with a browser (from the same machine)? — stovroz, Feb 26 '14 at 16:04
@stovroz The URL works fine in the browser on the same machine — Vlad, Feb 26 '14 at 16:05
BTW, can you duplicate this problem every single time or is this just happening intermittenly? — Kevin Le - Khnle, Feb 26 '14 at 16:12
Hmm - you don't actually have to close (do `using` on) the response stream here, but I didn't think doing so would be harmful. — 500 - Internal Server Error, Feb 26 '14 at 16:17

score 3 · Accepted Answer · edited May 23 '17 at 11:58

3

Simplifying things a bit and just doing a:

WebRequest.Create("https://www.bitstamp.net/api/ticker/").GetResponse();

I'm getting WebException "The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF", which apparently is indicative of a problem at the server end, and one (perhaps the only) way round it is to add the following to your config file:

<system.net> 
  <settings> 
    <httpWebRequest useUnsafeHeaderParsing="true" /> 
  </settings> 
</system.net>

Worked for me anyway.

edited May 23 '17 at 11:58

Community

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answered Feb 26 '14 at 16:32

stovroz

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In fact on a different computer, I was getting the "The server committed a protocol violation" error instead of the objectdisposed. Very strange. – Vlad Feb 26 '14 at 16:38

Strange object disposed exception on HttpWebResponse

1 Answers1