Hello Jason, with this way I got same errors ( I think to wrong the syntax )
I found a simple way like yours pre-built solutions, in the file 'waue_userdata_email_1.php'
I change around line 38...
////////////////////////////////////////////
//Start Mail Body
$MailBody = $MailBody . "";
$MailBody = $MailBody . (GetFromPage("templates/user_data_template.php"));
$MailBody = $MailBody . "";
//End Mail Body
////////////////////////////////////////////
with this
////////////////////////////////////////////
//Start Mail Body
$MailBody = $MailBody . "";
ob_start();
require_once(dirname(__FILE__) . ("/templates/user_data_template.php"));
$contents = ob_get_clean();
$MailBody = $MailBody . ($contents);
$MailBody = $MailBody . "";
//End Mail Body
////////////////////////////////////////////