Core Data crash: Keypath Project not found in entity

- (void)fetchResult
{
    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"Project" ascending:YES];

    [request setEntity:self.entityDescription];
    [request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
    self.fetchResultController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];

    NSError *fetchError = nil;
    BOOL success = [self.fetchResultController performFetch:&fetchError];
    if (success) {
        NSLog(@"fetched!");
    }
    else {
    NSLog(@"fetch fail!");
    }
}

The entityDescription and the context is set in the viewDidLoad method, as it is shown below:

AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
self.managedObjectContext = appDelegate.managedObjectContext;
self.entityDescription = [NSEntityDescription entityForName:@"Project" inManagedObjectContext:self.managedObjectContext];

Crash info: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath Project not found in entity '

Could anybody give a hand?;)

The key used in the sort descriptor

[NSSortDescriptor sortDescriptorWithKey:@"Project" ascending:YES];

must be a property of your Core Data entity, not the name of the entity itself. So you should replace @"Project" in the sort descriptor by some property of the Project entity, such as @"name".