What Does This NSZombie Error Message Mean?

I turned zombies on because I was getting some crashes. Now I' getting this error in console. Does anyone know what it means?

*** -[RoutineDayTableViewController retain]: message sent to deallocated instance 0x7464150

@implementation RoutineDayTableViewController

@synthesize fetchedResultsController;
@synthesize exerciseChooserView;
@synthesize routineTableView;
@synthesize managedObjectContext;
@synthesize selectedExercise;
@synthesize theSelectedRoutine;

- (void)dealloc
{
    NSLog(@"dealloc");
    [fetchedResultsController release];
    [selectedExercise release];
    [managedObjectContext release];
    [exerciseChooserView release];
    [routineTableView release];
    [theSelectedRoutine release];
    [super dealloc];
}

- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.routineTableView.delegate = self;
    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }
}

- (void)viewDidUnload
{
    NSLog(@"viewDidUnload");
    [super viewDidUnload];
    self.exerciseChooserView = nil;
    self.routineTableView = nil;
    self.fetchedResultsController = nil;
}

#pragma mark - Exercise Editing

-(IBAction)exerciseChooser
{
    RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];
    [self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
}

-(void)addExercise
{   
    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }

    UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
    self.navigationItem.rightBarButtonItem = addButton;
    [addButton release];

    NSError *error = nil;

    Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

    exercise.name = self.selectedExercise;

    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);

    [self.theSelectedRoutine addRoutineToExercisesObject:exercise];

    if (![fetchedResultsController.managedObjectContext save:&error]) 
    {
        // Handle the error.
    }
    NSLog(@"%@", error);
    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);
}



#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return [[self.fetchedResultsController sections] count];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
    return [sectionInfo numberOfObjects];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [routineTableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    Exercise *tempExercise = (Exercise *)[fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = tempExercise.name;

    return cell;
}

-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) 
    {
        // Delete the managed object for the given index path
        NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
        [context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
        NSLog(@"fetched results : \n%@\n",[self.fetchedResultsController fetchedObjects]);

        // Commit the change.
        NSError *error = nil;

        // Update the array and table view.
        if (![fetchedResultsController.managedObjectContext save:&error]) 
        {
            // Handle the error.
        }
        //[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
    }
}

- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
    NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = [[managedObject valueForKey:@"name"] description];
}

#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Navigation logic may go here. Create and push another view controller.
    [routineTableView deselectRowAtIndexPath:indexPath animated:YES];
     DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
     // Pass the selected object to the new view controller.
     [self.navigationController pushViewController:detailViewController animated:YES];
     [detailViewController release];
}

#pragma mark - Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController
{
    if (fetchedResultsController != nil)
    {
        return fetchedResultsController;
    }

    // Create the fetch request for the entity.
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    // Edit the entity name as appropriate.
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];
    NSLog(@"fetchedResultsController theSelectedRoutine: %@",theSelectedRoutine);
    [fetchRequest setPredicate:[NSPredicate predicateWithFormat: @"ANY exerciseToRoutine == %@", theSelectedRoutine]];

    // Set the batch size to a suitable number.
    [fetchRequest setFetchBatchSize:20];

    // Edit the sort key as appropriate.
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:NO];
    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

    [fetchRequest setSortDescriptors:sortDescriptors];

    // Edit the section name key path and cache name if appropriate.
    // nil for section name key path means "no sections".
    NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:开发者_开发百科self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController = aFetchedResultsController;

    NSError *error = nil;
    if (![self.fetchedResultsController performFetch:&error])
    {
        /*
         Replace this implementation with code to handle the error appropriately.

         abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
         */
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }

    [aFetchedResultsController release];
    [fetchRequest release];
    [sortDescriptor release];
    [sortDescriptors release];
    return fetchedResultsController;
}    

#pragma mark - Fetched results controller delegate

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
    [self.routineTableView beginUpdates];
}

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
    switch(type)
    {
        case NSFetchedResultsChangeInsert:
            [self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [self.routineTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath
{
    UITableView *tableView = self.routineTableView;

    switch(type)
    {

        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeUpdate:
            [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
            break;

        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
    [self.routineTableView endUpdates];
}

@end

Update, this method is in another viewController. Could this be causing the problem?

    - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
    {
        [tableView deselectRowAtIndexPath:indexPath animated:YES];

        NSString *selectedRow = [[self.exerciseArray objectAtIndex:indexPath.row]objectForKey:@"exerciseName"];
        NSLog(@"Row Selected: %@", selectedRow);

        RoutineDayTableViewController *routineDayTableViewController=[self.navigationController.viewControllers objectAtIndex:([self.navigationController.viewControllers count] -3)];

        routineDayTableViewController.selectedExercise = selectedRow;
        [routineDayTableViewController addExercise];
        [routineDayTableViewController release];

        [self dismissView];
  }

and here is another method in yet another viewController that access this class:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];

     RoutineDayTableViewController *detailViewController = [[RoutineDayTableViewController alloc] initWithNibName:@"RoutineDayTableViewController" bundle:nil];
    NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];

    detailViewController.title = [[managedObject valueForKey:@"name"] description];

    detailViewController.theSelectedRoutine = [__fetchedResultsController objectAtIndexPath: indexPath];
    NSLog(@"detailViewController.theSelectedRoutine:%@",detailViewController.theSelectedRoutine);
    [self.navigationController pushViewController:detailViewController animated:YES];
    [detailViewController release];
}

The error message means that you are sending a message to an object whose retain count went to zero and was subsequently deallocated. Based on your code snippet, I think your problem is this code -

    RoutineDayTableViewController *routineDayTableViewController=[self.navigationController.viewControllers objectAtIndex:([self.navigationController.viewControllers count] -3)];

    routineDayTableViewController.selectedExercise = selectedRow;
    [routineDayTableViewController addExercise];
    [routineDayTableViewController release];

The release call here looks suspicious. You are releasing something you haven't alloced here.

Have you run static analyzer on your code? It is helpful in detecting bugs of this kind.

The instance of the class RoutineDayTableViewController is the problem, so it's not likely in the code you posted here.

Check the code where you use this class.

It may help you to build using the Analyse option, this often detects the problem.

There are some place where the instance of RoutineDayTableViewController class is release and after that you are trying to access it.

If you want to check , Please don't release that object and try to run.