Coredata - “NSObjectInaccessibleException - CoreData could not fulfill a fault” - ios

Question

i have a problem in my iOS App, i receive this error:
“NSObjectInaccessibleException - CoreData could not fulfill a fault”
When i update the database, i do it from another thread and i have in that thread this method:
#interface UpdateDatabase : NSOperation
#property (nonatomic,copy) NSString *name;
#end
#implementation UpdateDatabase
- (void)mergeChanges:(NSNotification *)notification
{
AppDelegate *appController = (AppDelegate *)[[UIApplication sharedApplication] delegate];
NSManagedObjectContext *mainContext = [appController managedObjectContext];
// Merge changes into the main context on the main thread
[mainContext performSelectorOnMainThread:#selector(mergeChangesFromContextDidSaveNotification:)
withObject:notification
waitUntilDone:YES];
}
- (void)main {
AppDelegate *appController = (AppDelegate *)[[UIApplication sharedApplication] delegate];
self.managedObjectContext = [[NSManagedObjectContext alloc] init];
[self.managedObjectContext setUndoManager:nil];
[self.managedObjectContext setPersistentStoreCoordinator: [appController persistentStoreCoordinator]];
// Register context with the notification center
NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
[nc addObserver:self
selector:#selector(mergeChanges:)
name:NSManagedObjectContextDidSaveNotification
object:self.managedObjectContext];
[self checkForUpdate:self.name];
}
- (NSFetchedResultsController *)fetchedResultsController
{
if (__fetchedResultsController != nil) {
return __fetchedResultsController;
}
// Set up the fetched results controller.
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Serial" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"sectionNumber" ascending:NO];
NSArray *sortDescriptors = [NSArray arrayWithObjects: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:self.managedObjectContext sectionNameKeyPath:#"sectionNumber" 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.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return __fetchedResultsController;
}
- (void)checkForUpdate:(NSString *)name
{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Serial" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
//Controllo prima che la serie di cui voglio fare l'aggiornamento non sia in download, e non stia facendo già un aggiornamneto (caso mai per qualche strana ragione non ne siano partiti 2), prendo solo le altre.
[fetchRequest setPredicate:[NSPredicate predicateWithFormat:#"%K == %#", #"serialName",self.name]];
NSError *error;
NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
for (NSManagedObject *info in fetchedObjects) {
//i update the object
}
if (![self.managedObjectContext save:&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();
}
}
#end
and i launch a new nsoperation for every element in the core data database, then in the view where i have the UITableView, i have this:
- (NSFetchedResultsController *)fetchedResultsController
{
if (__fetchedResultsController != nil) {
return __fetchedResultsController;
}
// Set up the fetched results controller.
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Serial" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"sectionNumber" ascending:NO];
NSSortDescriptor *numberDayDescriptor = [[NSSortDescriptor alloc] initWithKey:#"numberOfDays" ascending:YES];
NSSortDescriptor *serialNameDescriptor = [[NSSortDescriptor alloc] initWithKey:#"serialName" ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObjects:sortDescriptor,numberDayDescriptor,serialNameDescriptor, 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:self.managedObjectContext sectionNameKeyPath:#"sectionNumber" cacheName:#"Master"];
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.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return __fetchedResultsController;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView 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.tableView;
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.tableView endUpdates];
}
Sometime the app crashes and some time don't crash, how i can handle this error? i have read some question about this problem on SO, and someone talk about remove the fetchbatchsize and the cache, what you think? where i wrong?
EDIT:
I have edited the code.