When I load an url like this: NSURL *downloadURL = [NSURL URLWithString:@http://www.apple.com]; NSURLRequest *request = [NSURLRequest requestWithURL:downloadURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60]; self.task = [session dataTaskWithRequest:request completionHandler:^(NSData * data, NSURLResponse * response, NSError * error) { // more code }]; [self.task resume];The value of the error argument in the callback block is always like:Error Domain=NSURLErrorDomain Code=-1200 An SSL error has occurred and a secure connection to the server cannot be made. UserInfo=0x7a77f6e0 {NSErrorFailingURLStringKey=https://www.apple.com/, NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, NSErrorFailingURLKey=https://www.apple.com/, NSLocalizedDescription=An SSL error has occurred and a secure connection to the server cannot be made., _kCFStreamErrorDomainKey=3, _kCFStreamErrorCodeKey=-9824}It seems even I requested the http resource, it always hit