Gform validation message ignored

I have some filters in my functions.php for localizing gf. eg:-

add_filter("gform_name_first", "change_name_first", 10, 2);
function change_name_first($label, $form_id){
return "Nombre";
}
add_filter("gform_validation_message", "change_message", 10, 2);
function change_message($message, $form){
return "<div class='validation_error'>Hay errores en el formulario, por favor corrígelos y envialo de nuevo</div>";
}

In the above, the gform_name_first filter works fine. The gform_validation_message is ignored and the default validation message is displayed.

How can I correctly set the validation message?

Thanks,