SimplePie is set to 10 seconds timeout in default. So if the feed has problem with speed then you can increase the time. The exact error that I got was "cURL error 28: Operation timed out after 10001 milliseconds with 0 bytes received".
Source code viewer
// Make sure SimplePie is included. // Initialize SimplePie Class. $simplepie = new SimplePie(); // Prolong timeout, default was 10 and was not enough. $simplepie->set_timeout(20); // Give rss feed url to SimplePie. $simplepie->set_feed_url($url); // Init initializes the feed download and parsing. $simplepie->init(); // If error occurs, show it. if ($simplepie->error()) { $error = $simplepie->error(); } else { }Programming Language: PHP