V150 - PHP 5.4 issue - Edit Order Button Not Working

[inklingsolutions]

My client is running V150 on PHP 5.4. We just moved to a server that's using PHP 5.4, i'm assuming the last server was using a different PHP version and that's why this error didn't come up.

If you click on the Edit button to edit a customers order we're gettting:

PHP Warning: Creating default object from empty value in C:\Inetpub\vhosts\xxxx.com\xxxx.com\store\includes\modules\payment\authorizenet_ aim.php on line 439

The lines of code in that area are:

 function admin_notification($zf_order_id) {
    global $db;
    $output = '';
    $aimdata->fields = array();
    require(DIR_FS_CATALOG . DIR_WS_MODULES . 'payment/authorizenet/authorizenet_admin_notification.php');
    return $output;
  } 

Again, we're on PHP 5.4 and a Windows Server.

Is there a workaround that I can imply for a temp fix in the time being until I get them to upgrade?

Thanks in advance,

Chad