title: iOS PFUser currentUser - Warning: A long-running operation is being executed on the main thread
body: <p>I am developing an iOS app using Parse and in my AppDelegate a check whether there is a user logged in or not the way the Parse docs tell you to:</p>
  
  <pre><code>if ([PFUser currentUser]) {
      // User Logged In - do stuff with the user
  } else {
     // No User Logged In - Show Login/Sign Up View Controller
  }
  </code></pre>
  
  <p>However, I get the warning "Warning: A long-running operation is being executed on the main thread." on the line [PFUser currentUser] all the time and the app crashes sometimes because of this. I've searched through Parse and all questions related to this have been removed for whatever reason and I am having a tough time figuring this out. I understand that warning but am unaware how to fix it. Any help would be greatly appreciated!</p>