Question

I’m using version 6.0.10.0 of the Facebook.dll from the SDK. We are beta testing our application and one of my users cannot login. The user is on an iMac using Chrome.

I am using the server side flow, not using the Facebook Javascript SDK at all.

Here is a snippet of server side code i’m using to retrieve data from Facebook… (This code came directly from a sample somewhere, so credit is due to that author 🙂 )

var fbClient = new FacebookClient();
        var oauthResult = fbClient.ParseOAuthCallbackUrl(pRequestUri);

        string accessToken = null;
        DateTime expires = DateTime.Now;       

        // Exchange the code for an access token
        dynamic result = fbClient.Get("/oauth/access_token", new
        {
            client_id = ConfigurationManager.AppSettings["FacebookAppId"],
            redirect_uri = pRedirectUri.AbsoluteUri,
            client_secret = ConfigurationManager.AppSettings["FacebookAppSecret"],
            code = oauthResult.Code,
        });
        accessToken = result.access_token;
        expires = DateTime.UtcNow.AddSeconds(Convert.ToDouble(result.expires));

        // Get the user's profile information
        dynamic me = fbClient.Get("/me",
        new
        {
            fields = "first_name,last_name,email,name",
            access_token = accessToken
        });

        // Read the Facebook user values
        string sfacebookId = me.id;
        string firstName = me.first_name;
        string lastName = me.last_name;
        string email = me.email;

Here is the detail of the exception from my logs.

(OAuthException - #100) Code was invalid or expired. 

This may be because the user logged out or may be due to a system error.

source="Facebook" detail="Facebook.FacebookOAuthException: (OAuthException - #100) Code  was invalid or expired. This may be because the user logged out or may be due to a system error.

Stack Trace:

at Facebook.FacebookClient.ProcessResponse(HttpHelper httpHelper, String responseString, Type resultType, Boolean containsEtag, IList`1 batchEtags)

at Facebook.FacebookClient.Api(HttpMethod httpMethod, String path, Object parameters, Type resultType)   

at Facebook.FacebookClient.Get(String path, Object parameters)

The query string returned from Facebook includes the parameter code and it has a value.

It is easy to see from the stack trace that the first .Get() method call in my code ends up calling the .ProcessResponse() method which throws the error.

Unfortunately, everywhere I search talks about what to do with an expired access token.

In my case, I have not even retrieved an access token yet, it is my code that is expired or invalid. How can I request a new code?

Thanks,

Answer 1

I could never get the server side flow working for all my users, so I went ahead and switched to the FB Javascript SDK and it is working for me now.