Notification in Vaadin 8.3.1

After I update my project from version 8.2.1 to 8.3.1 my notifications stop to show in Screen

that code works on 3.2.1 but don`t work in 8.3.1 why?"Teste","Teste", Notification.Type.ERROR_MESSAGE);

any javascript errors?

Did you remember to recompile widgetset? In latest version there has been a bug fix in Notifcation and client - server version mismatch may be the reason.