in your page you will see code similar to the following:
$WAFV_Errors .= WAValidateRQ(((isset($_POST["fileField"]))?$_POST["fileField"]:"") . "",false,1);
change that to:
$WAFV_Errors .= WAValidateRQ(((isset($_FILES["fileField"]))?$_FILES["fileField"]["name"]:"") . "",false,1);