Fatal error: NSArray element failed to match the Swift Array Element type

iOS
1

import Foundation

class Signupcode : NSObject {

var signupcode : String?
var usecount: Int?
var objectId : String?
var ownerId: String?
var created: NSDate?
var updated: NSDate?
//var owner : BackendlessUser?

}

2

I solved the issue. a typo, silly me. How to close this topic?