核心数据不会保存更改

我的代码有点问题，实际上我在使用RestKit在核心数据中映射各种对象，效果很好，然后我需要编辑某些对象，当我编辑它并保存上下文时，它们都非常有效很好，没有问题，麻烦是当我停止应用程序并再次打开它时，我所做的任何更改都没有保存，这是我的代码：

[managedObjectStore createPersistentStoreCoordinator];

NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"TaskModel.sqlite"];
NSString *seedPath = [[NSBundle mainBundle] pathForResource:@"RKSeedDatabase" ofType:@"sqlite"];
NSError *error;
NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:storePath fromSeedDatabaseAtPath:seedPath withConfiguration:nil options:nil error:&error];
NSAssert(persistentStore, @"Failed to add persistent store with error %@", error);

//create the managed object contexts
[managedObjectStore createManagedObjectContexts];

//Configure a managed object cache to ensure we do not create duplicate objects
managedObjectStore.managedObjectCache = [[RKInMemoryManagedObjectCache alloc] initWithManagedObjectContext:managedObjectStore.persistentStoreManagedObjectContext];

然后这是我的更新方法：

// Get data
    // 1.- Create the request object:
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

    NSManagedObjectContext *localContext = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext;
    // 3.- Define the type of managed object you need:
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"SavedTask" inManagedObjectContext:localContext];
    [fetchRequest setEntity:entity];
    [fetchRequest setReturnsObjectsAsFaults:NO];
    NSPredicate *searchTasktoComplete = [NSPredicate predicateWithFormat:@"taskId == %@", self.task.taskId];
    [fetchRequest setPredicate:searchTasktoComplete];
    // 5.- Execute the request:
    NSError *error;
    NSArray *fetchedTasks = [localContext executeFetchRequest:fetchRequest error:&error];

    SavedTask *taskToComplete = [fetchedTasks objectAtIndex:0];

    //complete the task in core data
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MM/dd/yyyy"];
    NSString *date = [dateFormat stringFromDate:[NSDate date]];
    [taskToComplete setRealDate:date];
    [taskToComplete setFollowUp:@"100"];
    [localContext refreshObject:taskToComplete mergeChanges:YES];
    [localContext save:&error];
    if (![localContext save:&error]) {
        NSLog(@"error");
    }

有人可以帮我吗？，在此先感谢