title: An Objective-C message was sent to a deallocated object (zombie) at address: 0x75d52a0
body: <p>I am relatively new to iOS development so appreciate your help in finding out the root cause for the error that I encountered.</p>
  
  <p>I tried to debug the error using Instruments (i.e. Allocations-Zombie Profiler) but I could not make sense of the call stacks that were presented.</p>
  
  <p>This is how the user interfaces are linked:
  TabBarController -> NavigationController -> TopPlacesTableViewController -> RecentPhotosTableViewController -> PhotoViewController</p>
  
  <p>The error occurs when I click on the Back button in the last view (i.e. that of the PhotoViewController). This action is supposed to show the previous RecentPhotosTableViewController but instead an unknown deallocated object was accessed, sometime in between the events of viewWillAppear and ViewDidAppear.</p>
  
  <p>Additionally, I have a GenericTableViewController which is the parent of TopPlacesTableViewController and RecentPhotosTableViewController. The children set a NSMutableArray property in the parent which is the data that gets loaded in the children's views.</p>
  
  <p>I am currently using iOS6 and XCode4.5.</p>
  
  <p>[Update: In the Console, this line was shown - "[UIView _forgetDependentConstraint:]: message sent to deallocated instance xxx"].</p>