title: FBSDKShareKit : Share Form does not prompt
body: <p>I just migrated to Facebook iOS SDK 4.0 (from 3.0).</p>
  
  <p>Sharing content is now done using the FBSDKShareKit framework. 
  I am currently using the following sample code as suggested by the documentation :</p>
  
  <pre><code>FBSDKShareLinkContent *content = [[FBSDKShareLinkContent alloc] init];
              content.contentURL = [NSURL URLWithString:@"http://www.apple.com"];
              FBSDKShareButton *button = [[FBSDKShareButton alloc] init];
              button.shareContent = content;
  </code></pre>
  
  <p>When I click on the button, I am redirected to the Facebook native app; but not sharing form is provided and nothing seems wrong according the console logs.</p>
  
  <p>Notice that :
   * The App-Info.plist is well configured including FacebookAppId, FacebookDisplayName, as well as the URL types.
   * The AppDelegate.m class includes the appropriate changes as mentioned in Facebook documentation</p>
  
  <p>Any reason why no form is prompted for the user to share the link?</p>