Cancel PayPal payment URL problem

Hello:

I am using OJS 2.4.2.0 version and have set up Paypal payment system by using “PayPal Fee Payment” option.

When users click continue button, they can reach the PayPal page. However, when the URL at the bottom of the page “Cancel and Return to xxx Site”, an error page returns with the following message:

Fatal error : Call to undefined method PayPalPlugin::getAuthorizedContextObject() in /home/xxx/public_html/lib/pkp/classes/handler/PKPHandler.inc.php on line 430

I don’t have a clue what could be wrong. Your help is greatly appreciated.

Thank you!