title: Obtaining the web lock from a thread other than the main thread or the web thread. UIKit should not be called from a secondary thread
body: <p>I am getting an error </p>
  
  <pre><code>Obtaining the web lock from a thread other than the main thread or the web thread. UIKit should not be called from a secondary thread
  </code></pre>
  
  <p>for the code <code>NSString *tokenString=[NSString stringWithFormat:@"username=%@&amp;password=%@",[[userName.text lowercaseString] MD5],[password.text MD5]];</code></p>
  
  <p>I am using class file for for MD5. i got it from <a href="http://iosdevelopertips.com/core-services/create-md5-hash-from-nsstring-nsdata-or-file.html" rel="nofollow">MD5</a></p>
  
  <p>This md5 causing the thread lock how can I remove this warning </p>