title: AFNetworking error in uploadTaskWithStreamedRequest
body: <p>Error</p>
  
  <pre><code>Terminating app due to uncaught exception 'NSGenericException', reason: 'Upload tasks in background sessions must be from a file'
  </code></pre>
  
  <p>when i try </p>
  
  <pre><code>NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
  </code></pre>
  
  <p><code>configuration</code> for <code>NSURLSession</code> work fine but when i use bellow <code>configuration</code> then application crash and give me error.</p>
  
  <pre><code>NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration backgroundSessionConfiguration:kBackgroundSessionIdentifier];
  </code></pre>