核心数据问题-EXC\u访问错误

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

NSEntityDescription *entity = [NSEntityDescription entityForName:@"TVShow" inManagedObjectContext:[self managedObjectContext]];
[fetchRequest setEntity:entity];

[fetchRequest includesPendingChanges];
//NSPredicate *predicate = [NSPredicate predicateWithFormat:@"ID == %@", showId];
//[fetchRequest setPredicate:predicate];

NSError *error;

NSLog(@"Generating Count");

NSUInteger count = [[self managedObjectContext] countForFetchRequest:fetchRequest error:&error];

if(count == NSNotFound) {
    NSLog(@"error");
}
else {
    NSLog(@"%@", count); // EXC_BAD_ACCESS here
}

[fetchRequest release];