My app is crashing when I assign the managed object context to a variable

Question

Pleeeease help. I'm making this app and I didn't add coreData in the beginning. I added it later with the help of some online tutorials. everything seems to be working fine except that my app is crashing at line 33 here:

import UIKit
import CoreData

class SittingsViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        //preperation
        Stepper.continuous = false
        Stepper.autorepeat = false
        Stepper.maximumValue = 6
        Stepper.minimumValue = 0
        valChanged(1)
        var request = NSFetchRequest(entityName: "Sittings")
        request.returnsObjectsAsFaults = false
        Stepper.value = managedContext.executeFetchRequest(request, error: nil) as! Double
        managedContext.save(nil)
}

//global vars and iboutlets
@IBOutlet var Stepper: UIStepper!
@IBOutlet var AproximateLabel: UILabel!
var decimalPlaces = Int()
    //core data
    var appDel = UIApplication.sharedApplication().delegate as! AppDelegate
    var managedContext = SittingsViewController().appDel.managedObjectContext! //my error happens here
    let entity =  NSEntityDescription.entityForName("Sittings",
        inManagedObjectContext:
        SittingsViewController().managedContext)
    let decimal = NSManagedObject(entity: SittingsViewController().entity!,
        insertIntoManagedObjectContext:SittingsViewController().managedContext)


@IBAction func stepperValueChanged(sender: UIStepper) {
    valChanged(Int(sender.value))
    AproximateLabel.text = Int(sender.value).description
}

//segue
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        var firstView: ViewController = segue.destinationViewController as! ViewController
        firstView.decimalPlaces = Int(decimalPlaces)
}

func valChanged(num: Int) {
    let entity =  NSEntityDescription.entityForName("Sittings",
        inManagedObjectContext:
        managedContext)
    let decimal = NSManagedObject(entity: entity!,
        insertIntoManagedObjectContext:managedContext)

    //3
    decimal.setValue(num, forKey: "decimalPlaces")

    //4
    var error: NSError?
    if !managedContext.save(&error) {
        println("Could not save \(error), \(error?.userInfo)")
    }  
    decimalPlaces = num
}
}

If you need more code or anything else, I would be happy to help!

---

Backtrace:

https://drive.google.com/file/d/0Bxu11l4-PozQTHk5cmYydlZ3Zm8/view?usp=sharing

---

AppDelegate:

import UIKit import CoreData

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?

func application(application: UIApplication, didFinishLaunchingWithOptions     launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    UIApplication.sharedApplication().statusBarStyle =     UIStatusBarStyle.LightContent
    return true
}

func applicationWillResignActive(application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

func applicationDidEnterBackground(application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(application: UIApplication) {
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

func applicationWillTerminate(application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    self.saveContext()
}

// MARK: - Core Data stack

lazy var applicationDocumentsDirectory: NSURL = {
    // The directory the application uses to store the Core Data store file. This code uses a directory named "com.xxxx.math" in the application's documents Application Support directory.
    let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
    return urls[urls.count-1] as! NSURL
    }()

lazy var managedObjectModel: NSManagedObjectModel = {
    // The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
    let modelURL = NSBundle.mainBundle().URLForResource("math", withExtension: "momd")!
    return NSManagedObjectModel(contentsOfURL: modelURL)!
    }()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
    // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
    // Create the coordinator and store
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("math.sqlite")
    var error: NSError? = nil
    var failureReason = "There was an error creating or loading the application's saved data."
    if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil {
        coordinator = nil
        // Report any error we got.
        var dict = [String: AnyObject]()
        dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
        dict[NSLocalizedFailureReasonErrorKey] = failureReason
        dict[NSUnderlyingErrorKey] = error
        error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
        // Replace this 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 coordinator
    }()

lazy var managedObjectContext: NSManagedObjectContext? = {
    // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
    let coordinator = self.persistentStoreCoordinator
    if coordinator == nil {
        return nil
    }
    var managedObjectContext = NSManagedObjectContext()
    managedObjectContext.persistentStoreCoordinator = coordinator
    return managedObjectContext
    }()

// MARK: - Core Data Saving support

func saveContext () {
    if let moc = self.managedObjectContext {
        var error: NSError? = nil
        if moc.hasChanges && !moc.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.
            NSLog("Unresolved error \(error), \(error!.userInfo)")
            abort()
        }
    }
}
}

Thank you very much!

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I just found out that my managedObjectContext is nil, but I don't know why? Can anybody help?