PubNub setup with Swift Xcode 7 beta 6

Question

I have setup pubnub with swift using a pods and a bridging header. In the ViewDidLoad of my ViewController I'm attempting to initialise it and it fails at

client?.subscribeToChannels(["My_Channel"], withPresence: false)

It is ultimately failing in PNClientState.m at:

- (NSDictionary *)stateMergedWith:(NSDictionary *)state forObjects:(NSArray *)objects {

    NSMutableDictionary *mutableState = [([self state]?: @{}) mutableCopy];

This had been working fine for days so it is confusing why it would suddenly fail?

Thanks for any assistance.