title: CoreData: error: Serious application error. Exception was caught during Core Data change processing
body: <p>I am running into major issues developing my iphone app. </p>
  
  <p>here is the full error:</p>
  
  <pre><code>CoreData: error: Serious application error.  Exception was caught during Core Data 
  change processing.  This is usually a bug within an observer of 
  NSManagedObjectContextObjectsDidChangeNotification.  -[TimeSpentStudying coordinate]:
  unrecognized selector sent to instance 0x21db92d0 with userInfo (null)
  </code></pre>
  
  <p>This is weird because I have two coreData entities ( Locations &amp;  TimeSpentStudying). But I dont think those are the problems. <code>[TimeSpentStudying coordinate]</code> is weird, because I do not have a <code>coordinate</code> property sent on <code>TimeSpentStudying</code> core data class</p>
  
  <p>I have a mapView set up, and when a user taps on the detail disclosure button on an mkannotationview, a new view (LibraryTrackTimeViewController) pops up, but is pretty much unusable. I tried calling NSLog in viewDidLoad and nothing showed up.</p>
  
  <p>mapViewController.m</p>
  
  <pre><code>#pragma mark - NSNotification
  
  - (void)contextDidChange:(NSNotification *)notification
  {
    if ([self isViewLoaded]) {
      [self updateLocations];
  }
  </code></pre>
  
  <p>.</p>
  
  <pre><code>- (void)updateLocations
  {
  NSEntityDescription *entity = [NSEntityDescription entityForName:@"Location" inManagedObjectContext:self.managedObjectContext];
  
  NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
  [fetchRequest setEntity:entity];
  
  NSError *error;
  NSArray * foundObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&amp;error];
      if (foundObjects == nil) {
      FATAL_CORE_DATA_ERROR(error);
      return;
      }
  
      if (locations != nil) {
      [self.mapView removeAnnotations:locations];
      }
  
  locations = foundObjects;
  [self.mapView addAnnotations:locations];
  </code></pre>
  
  <p>}</p>
  
  <pre><code>-(void)dealloc
  {
  [[NSNotificationCenter defaultCenter] removeObserver:self
      name:NSManagedObjectContextObjectsDidChangeNotification
      object:self.managedObjectContext];
  }
  </code></pre>
  
  <p>the error I think might have to do with the prepareForSegue method in mapViewController.m</p>
  
  <pre><code>-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
  {
    if (distance &lt; 500) {
    if ([segue.identifier isEqualToString:@"TrackLibraryTimes"]) {
      UINavigationController *navigationController = segue.destinationViewController;
  
  LibraryTrackTimeViewController *controller = (LibraryTrackTimeViewController *)navigationController.topViewController;
  controller.managedObjectContext = self.managedObjectContext;
    }
   }}
  </code></pre>
  
  <p>I apologize for the rough syntax, I am just getting used to SO, if you need any more code, please let me know, thanks all.</p>