title: 400 bad request for accessing a "http://Url/_vti_bin/listDate.svc" in sharepoint 2010 web service
body: <p>I tried to add a service reference to my windows form application in visual studio for accessing :</p>
  
  <p><a href="http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc" rel="nofollow">http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc</a> </p>
  
  <p>but after I click "go" button it returns an error with the following Details :</p>
  
  <blockquote>
    <p>There was an error downloading >'<a href="http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc" rel="nofollow">http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc</a>'.
    The request failed with HTTP status 400: Bad Request.
    Metadata contains a reference that cannot be resolved: >'<a href="http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc" rel="nofollow">http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc</a>'.
    The remote server returned an unexpected response: (400) Bad Request.
    The remote server returned an error: (400) Bad Request.
    If the service is defined in the current solution, try building the solution >and adding the service reference again.</p>
  </blockquote>
  
  <p>but when I enter the address in IE at first time it does not show anything but when I authenticate my self by visiting </p>
  
  <p><a href="http://intranet.contoso.com/sites/Lab05" rel="nofollow">http://intranet.contoso.com/sites/Lab05</a></p>
  
  <p>IE will shows some xml information after entering </p>
  
  <p><a href="http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc" rel="nofollow">http://intranet.contoso.com/sites/Lab05/_vti_bin/ListData.svc</a></p>
  
  <p>address.</p>
  
  <p>I do these works in windows server 2008 R2 and visual studio 2012 on the same machine which Windows is installed.</p>