Attempting to load the view of a view controller while it is deallocating is not allowed and may result in undefined behavior
<blockquote>
  <p>Attempting to load the view of a view controller while it is deallocating is not allowed and may result in undefined behavior </p>
</blockquote>

<p>This warning appear just once. I alloc the <code>UIAlertView</code> in a base:</p>

<pre><code>viewController's viewDidLoad`self.alertView = [[UIAlertView alloc] initWithTitle.....`,
</code></pre>

<p>and</p>

<pre><code> `- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    self.alertView = nil;
}`
</code></pre>

<p>viewController A and viewController B inherit from the base viewController. </p>

<p>When this viewController A push to a viewController B the warning appear but B pop to A and A push to B again ,this warning doesn't appear.</p>

<p>When I use the simulator (iOS 9.2), the warning appears, but when I use an iPhone (iOS 8.2), it doesn't appear.</p>