_BSMachError XCode 7 Beta

Question

I am getting the following error when I am running my code in Xcode7 with Swift2, after presenting a view controller through a push segue:

_BSMachError: (os/         


        

Answer 1

I make like that

 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) { () -> Void in
        AnswersDataServerEntity.saveSingleDocoment(doc)
    }