ListData.svc returns Error 400: Bad Request in Visual Studio

Question

I wanted to use the REST Service in an application. So when I add the service reference in Visual Studio I get this error

There was an error downloading 'http://myMainSite/sites/subSite/_vti_bin/ListData.svc'. The request failed with HTTP status 400: Bad Request. Metadata contains a reference that cannot be resolved: 'http://myMainSite/sites/subSite/_vti_bin/ListData.svc'. The remote server returned an unexpected response: (400) Bad Request.

When I access the Service-URL in the browser I get the definition xml

Answer 1

i also got it and solved ..

1. temporarily turn off anonymous authentication on the web application... this can be done as...

Open Internet Information Services (IIS) Manager:

If you are using Windows Vista or Windows 7: On the taskbar, click Start, and then click Control Panel. Double-click Administrative Tools, and then double-click Internet Information Services (IIS) Manager. In the Connections pane, expand the server name, expand Sites, and go to the level in the hierarchy pane that you want to configure, and then click the Web site or Web application. Scroll to the Security section in the Home pane, and then double-click Authentication. In the Authentication pane, select Anonymous Authentication, and then click Disable in the Actions pane.

Answer 2

The authentication under _vti_bin should be only 'Windows' and not 'Anonymous'. So you need to change it from IIS.

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Reason : The mex endpoint uses mexHttpBinding which is configured to use Windows Auth in web.config ( in 14\ISAPI folder);

<binding name="mexHttpBinding">
          <security mode="TransportCredentialOnly">
            <transport clientCredentialType="Windows" proxyCredentialType="Windows"/>
          </security>
        </binding>