Error after updating core data model - Unrecognized selector sent to instance

Question

I get the following error after adding a string property called Unique Identifier to my Enitiy/NSManagedObject called Labels. However it is not the Unique Identifier which the complier is unhappy with.

2016-08-20 02:20:08.394 AN[22499:8730414] -[AN.Labels folders]: unrecognized selector sent to instance 0x7ffe907e1a80 2016-08-20 02:20:08.405 AN[22499:8730414] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[AN.Labels folders]: unrecognized selector sent to instance 0x7ffe907e1a80'

Here's my NSManagedObject class

class Labels: NSManagedObject {

    @NSManaged var title: String?
    @NSManaged var details: String
    @NSManaged var date: NSDate?
    @NSManaged var uniqueIdentifier: NSString?

    @NSManaged var arrayOfFolders: [Folders]
    @NSManaged var folder: Folders?
    @NSManaged var folders: NSSet

    override func awakeFromFetch() {
        super.awakeFromFetch()
        self.regenerateFolders()
    }

    func regenerateFolders() {
        let date = NSSortDescriptor(key: "date", ascending: false)
        if let array = folders.sortedArrayUsingDescriptors([date]) as? [Folders] {
            self.arrayOfFolders = array
        }
    }    
}

I have made sure the app uses the new coreData model and have the following in my CoreData Stack. I haven't had this issue for some time as my app automatically updates to use the latest core data model.

var storeDirectoryURL: NSURL {
    return try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true)
}

var storeURL: NSURL {
    return self.storeDirectoryURL.URLByAppendingPathComponent("SingleViewCoreData.sqlite")
}

func setupCoreData() {
    let modelURL = NSBundle.mainBundle().URLForResource("AN", withExtension: "momd")
    let model = NSManagedObjectModel(contentsOfURL: modelURL!)

    try! NSFileManager.defaultManager().createDirectoryAtURL(self.storeDirectoryURL, withIntermediateDirectories: true, attributes: nil)

    let coordinator = NSPersistentStoreCoordinator(managedObjectModel: model!)
    let options = [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true]
    try! coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: self.storeURL, options: options)

    managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
    managedObjectContext.persistentStoreCoordinator = coordinator
    managedObjectContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy   
}

Does anybody have any suggestions ?

Answer 1

Check the relationship between Labels and Folders in the core data model. You may have the inverse relationship named something other than Labels.