title: Why is the background missing on my tab bar?
body: <p>The background is missing on my tab bar on iOS 7 in some cases. See screen shot:</p>
  
  <p><img src="https://i.stack.imgur.com/mgdGW.png" alt="enter image description here"></p>
  
  <p>I've subclassed UITabBarController and presented my subclass modally like so:</p>
  
  <pre><code>[self.navigationController presentViewController:tabBarController animated:NO completion:nil];
  </code></pre>
  
  <p>Sometimes, though it's rare, the background just doesn't show up on my tab bar, and I can see right through it. No translucent view - just transparency...</p>
  
  <p>I've debugged using the excellent <a href="http://revealapp.com" rel="nofollow noreferrer">Reveal app</a> and found that when I observe the problem, the _UITabBarBackgroundView is missing from the UITabBar at runtime (it should be a subview of UITabBar). And in case it's worth noting, the UIImageView is also missing from the UITabBar when the background is missing.</p>
  
  <p>I'm at a loss. What could be causing the tab bar to be missing its _UITabBarBackgroundView subview?</p>