PHP Warning when viewing Order

I am getting the following PHP warning when choose to view an order:

Warning: Undefined array key “action2” in /homepages/4/d902356905/htdocs/clickandbuilds/TheBeerfulness/wp-content/plugins/easy-paypal-events-tickets/includes/private_orders.php on line 8

I did fix this already on my site but i would appreciate when an update in the future wouldnt overwrite my change. Besides i am wondering why others dont get this.

Thank you for this nice plugin btw…