iPhone 7 NSUserDefaults变成了零

Question

I have an iPhone 7 , and I also use it for development. I noticed that in my app , I was storing a session token for auto login purposes into the NSUserDefaults. But sometimes , without removing it the session token was nil and the auto login is not working. This also happens to other apps , where some times it asks me to login again , although I already have. I am guessing that somehow to NSUserDefaults that most of the apps use are being erased somehow. Anyone having a similar issue ?

class func setSessionToken(_ token: String){
        let defaults = UserDefaults.standard
        defaults.setValue(token, forKey: sessionTokenKey)
        defaults.synchronize()
    }

class func getSessionToken()->String?{
        let defaults = UserDefaults.standard
        return defaults.string(forKey: sessionTokenKey)
    }

Answer 1

This issue normally occurs when Running an iOS8 or 9 simulator followed by an iOS10 simulator and NSUserDefaults stop working in the simulator.

But, in your case if it is not working in iPhone also . You can try it with latest version of Xcode8 .