PPV PayPal Sandbox error in paypal-express.pgp

I just installed PPV and am checking it out in PayPal sandbox mode.

Everything was going along fine, but when I confirmed the payment to view the protected content I received this error: Warning: setcookie() expects parameter 3 to be long, string given in /nfs/c05/h02/mnt/160593/domains/holographichealingcenter.com/html/wp-content/plugins/pay-per-view/includes/paypal-express.php on line 474

Warning: Cannot modify header information - headers already sent by (output started at /nfs/c05/h02/mnt/160593/domains/holographichealingcenter.com/html/wp-content/plugins/pay-per-view/includes/paypal-express.php:474) in /nfs/c05/h02/mnt/160593/domains/holographichealingcenter.com/html/wp-includes/pluggable.php on line 876

My test site is http://holographichealingcenter.com

Thank you!