title: UIApplication.shared.isNetworkActivityIndicatorVisible crash when setting to false
body: <p>I have a huge issue with my app. Whenever I set: </p>
  
  <pre><code>UIApplication.shared.isNetworkActivityIndicatorVisible = false
  </code></pre>
  
  <p>after I had previously set it to true, I get an NSZombie which shows the following:</p>
  
  <p>"An Objective-C message was sent to a deallocatedUIActivityIndicatorView' object (zombie) at address: 0x102b334d0</p>
  
  <p>Can't add images because I don't have the reputation yet.. :(</p>
  
  <p>but here are the links:</p>
  
  <p><a href="https://imgur.com/3i7TeSV" rel="nofollow noreferrer">http://imgur.com/3i7TeSV</a></p>
  
  <p><a href="https://imgur.com/E2oUq4e" rel="nofollow noreferrer">http://imgur.com/E2oUq4e</a></p>
  
  <p>I am pretty lost here. My project is both in Swift and Objective-C. I have been doing research for the last 24 hours and couldn't find anything. The app only crashes on device, in the simulator it works perfectly. </p>
  
  <p>Thanks for the help! </p>