500/503 error in Cart and Checkout

If the you see the 500 Internal Server Error or 503 Service Unavailable errors on the Cart and Checkout pages while the plugin is activated, and don’t see them if plugin is not active, try the following to workaround the issue:

— Deactivate Zend Guard Loader PHP extension. It’s used to load encrypted PHP scripts which WordPress users don’t usually use.

— Switch from PHP 5.3 to PHP 5.4+ (5.6 recommended).

If you are not sure how to that contact your hosting support.