title: UINavigationControllers are not allowed in a navigation controller in iOS7
body: <p>One of my apps refuses to launch and am getting this exception in iOS7.  The wording in the excpetion looks like a tantrum thrown by an engineer, especially the exclamation point.  The code runs fine in iOS 5/6 and has no warnings associated with it.  There is neither a warning in xcode 5.  Including an abbreviated code slice.  The reason I have done this is creating my own custom tabbar, which controls the entire navigation of the app.</p>
  
  <pre><code>2013-06-10 22:24:52.862 [3375:c07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'UINavigationControllers are not allowed in a navigation controller!'
  
  *** First throw call stack:
  (0x2c56028 0x29da902 0x1009873 0x2cd22fd 0x2cd2232 0x2c4fae5 0x1009716 0x100943f 0x1008ec5 0x9905 0xef05f9 0xef0daa 0xef21dc 0xf07c6c 0xf081d9 0xef3e55 0x3d6ace2 0x3d6a7ed 0x2bd18d5 0x2bd160a 0x2bfc032 0x2bfb59f 0x2bfb3eb 0xef1960 0xef3b6b 0x8e2d 0x8d95)
  libc++abi.dylib: terminating with uncaught exception of type NSException
  </code></pre>
  
  <p>Code:</p>
  
  <pre><code>UIViewController *homeController, *contactController, *procedureController, *wizardController, *teamController, *askController;
  
  homeController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
  UINavigationController *homeNavController = [[UINavigationController alloc] initWithRootViewController:homeController];
  
  wizardController = [[ProcedureWizardController alloc] initWithNibName:@"ProcedureWizardController" bundle:nil];
  UINavigationController *wizardNavController = [[UINavigationController alloc] initWithRootViewController:wizardController];
  
  askController = [[AskViewController alloc] initWithNibName:@"AskViewController" bundle:nil];
  UINavigationController *askNavController = [[UINavigationController alloc] initWithRootViewController:askController];
  
  teamController = [[TeamViewController alloc] initWithNibName:@"TeamViewController" bundle:nil];
  UINavigationController *teamNavController = [[UINavigationController alloc] initWithRootViewController:teamController];
  
  procedureController = [[ProcedureViewController alloc] initWithNibName:@"ProcedureViewController" bundle:nil];
  UINavigationController *procNavController = [[UINavigationController alloc] initWithRootViewController:procedureController];
  
  
  contactController = [[ContactViewController alloc] initWithNibName:@"ContactViewController" bundle:nil];
  UINavigationController *contactNavController = [[UINavigationController alloc] initWithRootViewController:contactController];
  
  viewControllers = [NSArray arrayWithObjects:homeNavController, wizardNavController, askNavController, teamNavController, procNavController, contactNavController, nil];
  
  navController = [[UINavigationController alloc] init];;
  
  navController.viewControllers = [NSArray arrayWithArray:viewControllers];
  </code></pre>