Fix App Store submittion Reject issue iOS 11 on Wi-Fi connected to an IPv6 network

My app is rejected due to not supporting IPv6 network support. Here is message from Apple: We discovered one or more bugs in your app when reviewed on iPhone running iOS 11 on Wi-Fi connected to an IPv6 network. Submitting a Tweet through the app does not post it on the feed or on the Twitter web-site. My app is very simple and posts text using RestAPI call. Here is code snippet. let client = TWTRAPIClient(userID: userid) let url = "[login to view URL]"; let message:[String:Any] = ["status": text ] var error: NSError? let request = [login to view URL](withMethod: "POST", url: url, parameters: message, error: &error) [login to view URL] { [login to view URL](request) { (response, data, connectionError) -> Void in if let error = connectionError { print("Error: \([login to view URL])") [login to view URL] { completion(error) } } else { [login to view URL] { completion(nil) } } } } Did anyone experience this? This is very urgent job and I need this to be done today.