If you're getting a null NSURLResponse

[lipidfish]

This one had me hung up for a while. In [SonosDiscovery discoverControllers]the NSURLSession produced a null NSURLResponse, even though pasting the URL into a browser produced a valid response.

This is because in iOS 9, the default behavior is to not allow clear-text HTTP sessions. Since the URL starts with http://, (i.e. not https://), there will be no response sent back, and the NSError object contains a message alerting you to this.

To work around this, see this article

[kalms]

Caught the same thing yesterday. Been migrating it all to Swift 2.0 (because I'm bored and seems like a good chance to get into Swift)