Error when submitting download task with background session in Swift

Question

When I try to submit a download URL by using a background session created in this way:

func backgroundSession() -> NSURLSession?{
    var session:NSURLSession?;
    var configuration:NSURLSessionConfiguration!;
    if NSURLSessionConfiguration.respondsToSelector(Selector("backgroundSessionConfigurationWithIdentifier:")){
        configuration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier("myBackgroundSessionIdentifier\(++counter)")
    }
    else{
        configuration = NSURLSessionConfiguration.backgroundSessionConfiguration("myBackgroundSessionIdentifier\(++counter)")
    }
    configuration.allowsCellularAccess = true;
    configuration.timeoutIntervalForRequest = 20.0;
    configuration.timeoutIntervalForResource = 40.0;
    configuration.HTTPMaximumConnectionsPerHost = 1;
    configuration.networkServiceType = .NetworkServiceTypeBackground;
    configuration.discretionary = false;
    let queue=NSOperationQueue.mainQueue()
    session = NSURLSession(configuration:configuration, delegate:self, delegateQueue:queue)
    return session;
}

The app crashes with:

CFNetwork SSLHandshake failed (-9810)

when I submit the relative task with:

let url=NSURL(fileURLWithPath: escapedUrlString!);
let task = backgroundSession()?.downloadTaskWithURL(url!, completionHandler: {[weak self](data, reponse, error) in
        //UIApplication.sharedApplication().applicationIconBadgeNumber = 3;
    })
task!.resume()

While if I do the same by using a standard session created with:

 NSURLSession.sharedSession()

the connection goes without problems, but of course stops being submitted when the app becomes inactive.

What might be the problem at the base of the error?

Answer 1

I lost the reference to this thread, but the problem got resolved in some way.