Automattic developers released it yesterday evening new edition WordPress 4.9.3: The updated version of the popular CMS (from content management system) is a maintenance release and comes to fix 34 bugs of 4.9.
But today (just now) Automattic has released the WordPress 4.9.4 version. The new version brings a fix to the automatic updates, which according to the company were not working properly.
That's it change log says:
This maintenance release fixes a severe bug in 4.9.3, which will cause sites that support automatic background updates to fail to update automatically, and will require action from you (or your host) for it to be updated to 4.9.4.
Of course as with any update, you should upgrade immediately, either with the λήψη of application from the official website, or from your admin panel in automatic mode.
Before proceeding with the upgrade it would be good to get a full one backup.