title: (OAuthException) Error validating access token w/dynamic user = FbApp.Get("me") on Facebook C# SDK
body: <p>I use the Facebook C# SDK to build my membership system. When a user hits the site it does this:</p>
  
  <pre><code>FbApp = new FacebookApp();
  if (FbApp.Session != null) {
      // boom, they're in - get they're profile
  
      if (profile != null) {
          // sweet, they're already a member - load data to viewdata
      }
      else {
          // the fb session is active, but they are not yet a member
          try {
              dynamic user = FbApp.Get("me");
                      // ... save to db
          }
          catch (Exception exc) {
              // handle error
          }
      }
  }
  else {
      // no session - they're not logged in
  }
  </code></pre>
  
  <p>You can see it first checks for an active session. If there is one, pull their profile from the db. If they don't have one, query facebook with FbApp.Get("me") to get their data. Was working great.</p>
  
  <p>Then I got a report of an error occurring when someone logs in for the first time. So on my dev box, I set the facebook app ID to my alternate (test) facebook app, delete my local profile from the local db, remove my facebook account's access to the site and then hit the test site.</p>
  
  <p>It's supposed to just ask me for access, then pull my info from facebook and store it.</p>
  
  <p>Instead I'm getting: (OAuthException) Error validating access token.</p>
  
  <p>I've made sure I'm logged out of facebook, deleted all facebook/my domain cookies... but I can't get it to read my facebook profile.</p>
  
  <p>Any ideas?</p>