Yes, it's true: This is because the function session_is_registered() has been *REMOVED* as of PHP 5.4! This was an unhappy surprise and I found out the hard way. Here is some proof: http://php.net/manual/en/function.session-is-registered.php Now my ecommerce site is no longer working. I'm stuck with aMember 3 until you provide a Beanstream payment plugin to aMember 4. It's not easy for me to rollback to PHP 5.3, so I'll need a workaround.