title: UIWebView random crash at [UIViewAnimationState release]: message sent to deallocated instance
body: <p>I'm having a random <code>UIWebView</code> crash using <strong>iOS8.1</strong> and <code>UIWebView</code>, using an <strong>iPhone5</strong>. In my tests the crash doesn't appear on <strong>iOS7</strong>.</p>
  
  <p>I've created this github repository to reproduce the crash:
  <a href="https://github.com/crarau/WebViewCrash">https://github.com/crarau/WebViewCrash</a></p>
  
  <p>Basically I'm adding a <code>UIWebView</code> and loading www.amazon.com</p>
  
  <p>Randomly the app is crashing on the <code>WebThread</code> with <code>EXC_ARM_BREAKPOINT</code></p>
  
  <p>After enabling <strong>Zombie tracking</strong> on the console there is this message: </p>
  
  <pre><code>[UIViewAnimationState release]: message sent to deallocated instance 0x14deff70
  </code></pre>
  
  <p>Here what happens on <code>UIView</code> load:
  </p>
  
  <pre><code>[super viewDidLoad];
  
  NSURLRequest * urlRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.amazon.com"]];
  
  self.webView.layer.cornerRadius = 0;
  self.webView.userInteractionEnabled = YES;
  self.webView.multipleTouchEnabled = YES;
  self.webView.backgroundColor = [UIColor clearColor];
  self.webView.scrollView.scrollEnabled = NO;
  self.webView.scrollView.bounces = NO;
  [self.webView loadRequest:urlRequest];
  </code></pre>
  
  <p>The exception stacktrace:</p>
  
  <pre><code>    Exception Type:  EXC_BREAKPOINT (SIGTRAP)
      Exception Codes: 0x0000000000000001, 0x000000000000defe
      Triggered by Thread:  2
  
      Thread 0 name:  Dispatch queue: com.apple.main-thread
      Thread 0:
      0   libsystem_kernel.dylib          0x2fe054f0 mach_msg_trap + 20
      1   libsystem_kernel.dylib          0x2fe052e4 mach_msg + 36
      2   CoreFoundation                  0x21fed936 __CFRunLoopServiceMachPort + 142
      3   CoreFoundation                  0x21febedc __CFRunLoopRun + 1012
      4   CoreFoundation                  0x21f3a20c CFRunLoopRunSpecific + 472
      5   CoreFoundation                  0x21f3a01e CFRunLoopRunInMode + 102
      6   GraphicsServices                0x293330a4 GSEventRunModal + 132
      7   UIKit                           0x255461cc UIApplicationMain + 1436
      8   WebViewCrash                    0x0002deec main (main.m:14)
      9   libdyld.dylib                   0x2fd52aac start + 0
  
      Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
      Thread 1:
      0   libsystem_kernel.dylib          0x2fe052a0 kevent64 + 24
      1   libdispatch.dylib               0x00162674 0x154000 + 58996
      2   libdispatch.dylib               0x00157496 0x154000 + 13462
  
      Thread 2 name:  WebThread
      Thread 2 Crashed:
      0   CoreFoundation                  0x2202aea2 ___forwarding___ + 534
      1   CoreFoundation                  0x21f5cdf4 _CF_forwarding_prep_0 + 20
      2   CoreFoundation                  0x21f2ee58 CFRelease + 596
      3   QuartzCore                      0x24f0ba60 CA::release_objects(X::List&lt;void const*&gt;*) + 12
      4   QuartzCore                      0x24f10dc2 -[CAAnimation dealloc] + 50
      5   libobjc.A.dylib                 0x2f7ecd5a objc_object::sidetable_release(bool) + 162
      6   libobjc.A.dylib                 0x2f7ed1a4 (anonymous namespace)::AutoreleasePoolPage::pop(void*) + 400
      7   CoreFoundation                  0x21fee2a4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 12
      8   CoreFoundation                  0x21fede1e __CFRunLoopDoTimer + 646
      9   CoreFoundation                  0x21fec06e __CFRunLoopRun + 1414
      10  CoreFoundation                  0x21f3a20c CFRunLoopRunSpecific + 472
      11  CoreFoundation                  0x21f3a01e CFRunLoopRunInMode + 102
      12  WebCore                         0x2d362ebe RunWebThread(void*) + 414
      13  libsystem_pthread.dylib         0x2fe95e90 _pthread_body + 136
      14  libsystem_pthread.dylib         0x2fe95e02 _pthread_start + 114
      15  libsystem_pthread.dylib         0x2fe93b8c thread_start + 4
  </code></pre>
  
  <p>Any advice is appreciated
  Thanks</p>