title: EXC_BAD_ACCESS code=2 address=0x0
body: <p>I am using a UIActivityViewController in my app, and I am getting a EXC_BAD_ACCESS code=2 crash on iOS 6, but not iOS 7. Here is the code:</p>
  
  <pre><code>NSArray *activityItems;
  
  NSString *shareText = [NSString stringWithFormat:NSLocalizedString(@"Listen to", nil), self.currentChannel.title, self.currentChannel.itunesUrl];
  
  if (self.currentChannel.mediumThumbnailImage)
  {
      activityItems = @[shareText, self.currentChannel.mediumThumbnailImage];
  }
  else
  {
      activityItems = @[shareText];
  
  }
  
  UIActivityViewController *activityController = [[UIActivityViewController alloc]
                                                  initWithActivityItems:activityItems
                                                  applicationActivities:nil];
  
  [activityController setCompletionHandler:^(NSString *activityType, BOOL completed) {
      // once they have shared, check where they shared the content for analytics
      if (completed)
      {
          NSString *actionName = nil;
          NSString *socialName = nil;
          if ([activityType isEqualToString:kMailActivity]) {
              actionName = kSocialEmail;
              socialName = kMail;
          } else if ([activityType isEqualToString:kMessageActivity]) {
              actionName = kSocialChat;
              socialName = kMessage;
          } else if ([activityType isEqualToString:kFacebookActivity] || [activityType isEqualToString:kTwitterActivity]) {
              actionName = kSocialShare;
              socialName = kFacebook;
          }
  
          if (actionName &amp;&amp; socialName)
          {
              NSDictionary *data = @{kSocialName: socialName, kSocialContent: shareText};
              if (data)
              {
                  [ADBMobile trackAction:actionName data:data];
              }
          }
      }
  }];
  
  if (activityController)
  {
      [activityController setExcludedActivityTypes:
       @[UIActivityTypeAssignToContact,
         UIActivityTypePrint,
         UIActivityTypePostToWeibo,
         UIActivityTypeSaveToCameraRoll,
         UIActivityTypeAirDrop]];
  
      [self presentViewController:activityController
                         animated:YES completion:nil];
  }
  </code></pre>
  
  <p>I have used NSZombies to narrow down where the crash is happening, and it is happening when I call <code>setExcludedActivityTypes:</code> in iOS 6. I know that this error means that an object has been overreleased, and I am touching memory that doesn't belong to me. What I don't understand is why this crash is only occurring in iOS 6. Does anyone see something that could be causing this? </p>