Unable to save data to core data in xcode 8 even after adding new syntax

Question

@IBAction func createaccBtn(_ sender: UIButton) {

    if (firstNameText.text!.isEmpty || lastNameText.text!.isEmpty || userNameText.text!.isEmpty || emailIdText.text!.isEmpty || mobileNumText.text!.isEmpty || passwordText.text!.isEmpty || rePasswordText.text!.isEmpty){

        let alert = UIAlertController(title: "Oops!", message:"This feature isn't available right now", preferredStyle: .alert)
        let action = UIAlertAction(title: "OK", style: .default) { _ in
        }
        alert.addAction(action)
        self.present(alert, animated: true){}
    }
    else{

        let managedContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
        let entity =  NSEntityDescription.entity(forEntityName: "UserDetails", in:managedContext)
        let registerdetails = UserDetails(entity: entity!, insertInto: managedContext)
        registerdetails.setValue(firstNameText, forKey: "firstname")
        registerdetails.setValue(lastNameText, forKey: "lastname")
        registerdetails.setValue(userNameText, forKey: "username")
        registerdetails.setValue(emailIdText, forKey: "emailid")
        registerdetails.setValue(mobileNumText, forKey: "mobileno")
        registerdetails.setValue(passwordText, forKey: "password")
        registerdetails.setValue(gender, forKey: "gender")
        registerdetails.setValue(role, forKey: "role")
        do {
            try managedContext.save()
            print("saved")
        } catch let _ as NSError {
            print("NOt saved to databse")
        }
        let alert = UIAlertController(title: "congo!", message:"Saved", preferredStyle: .alert)
        let action = UIAlertAction(title: "OK", style: .default) { _ in
            self.performSegue(withIdentifier: "create to home", sender: self)
        }
        alert.addAction(action)
        self.present(alert, animated: true){}
    }
}

getting (lldb) error

Exact error

2016-10-01 19:17:16.478600 pmtry[1386:38006] subsystem: com.apple.UIKit, category: HIDEventFiltered, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:16.481130 pmtry[1386:38006] subsystem: com.apple.UIKit, category: HIDEventIncoming, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:16.489143 pmtry[1386:37999] subsystem: com.apple.BaseBoard, category: MachPort, enable_level: 1, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0, enable_private_data: 0 2016-10-01 19:17:16.504364 pmtry[1386:37960] subsystem: com.apple.UIKit, category: StatusBar, enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:16.546696 pmtry[1386:37960] subsystem: com.apple.BackBoardServices.fence, category: App, enable_level: 1, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0, enable_private_data: 0 2016-10-01 19:17:17.874474 pmtry[1386:37960] subsystem: com.apple.UIKit, category: Touch, enable_level: 0, persist_level: 0, default_ttl: 1, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:17.875397 pmtry[1386:37960] subsystem: com.apple.UIKit, category: Gesture, enable_level: 0, persist_level: 0, default_ttl: 1, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:17.876441 pmtry[1386:37960] subsystem: com.apple.UIKit, category: GestureEnvironment, enable_level: 0, persist_level: 0, default_ttl: 1, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:17.876921 pmtry[1386:37960] subsystem: com.apple.UIKit, category: GestureExclusion, enable_level: 0, persist_level: 0, default_ttl: 1, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 1, privacy_setting: 2, enable_private_data: 0 2016-10-01 19:17:19.274319 pmtry[1386:37960] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /Users/smit/Library/Developer/CoreSimulator/Devices/C3E3A9DB-1FF2-4F0B-BDA7-DEED56AEA019/data/Containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles 2016-10-01 19:17:19.274685 pmtry[1386:37960] [MC] Reading from private effective user settings. 2016-10-01 19:17:19.300471 pmtry[1386:37960] subsystem: com.apple.BackBoardServices.fence, category: Observer, enable_level: 1, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0, enable_private_data: 0 2016-10-01 19:17:19.300751 pmtry[1386:37960] subsystem: com.apple.BackBoardServices.fence, category: Workspace, enable_level: 1, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0, enable_private_data: 0 2016-10-01 19:17:19.301014 pmtry[1386:37960] subsystem: com.apple.BackBoardServices.fence, category: Trace, enable_level: 1, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0, enable_oversize: 0, privacy_setting: 0, enable_private_data: 0

(lldb)