On the night of November 15, 2017, the news was released WordPress 4.9 Billy Tipton, in honor of the jazz musician of the same name. The new WordPress 4.9 came to make tasks like designing your page easier, but also to keep you safe from code mistakes. 
Last night, Automattic released the first fix of 4.9, (4.9.), which is closing some gaps in security discovered in the previous version.
So, according to developers, the following were fixed:
- #42573: File caching affecting users' ability to use the plugin and theme file editors.
- #42574: MediaElement upgrade causing JS errors when certain languages are in use.
- #42579: Incorrect logic in
extract_from_markers(). - #42454: Can not translate Codex URL into theme editor.
- #42609: Theme editor cannot edit files when running on a Windows server.
- #42628:
flatten_dirlist()doesn't play nice with folders with numeric names. - #42634:
DB_HOSTsocket paths with colons not parsed correctly. - #42641: On multisite upgrade
wp_blog_versionstable doesn't get updated - #42673: Themes page throws console error when there is only one installed theme.
Let's note, however, that 57 is the version that brings many important internal changes:
Η application The Customizer has more features that allow you to final save, schedule or save a draft of the changes you made to your page theme.
So you can design your site with ease, and schedule when the changes you've made will be live.
Download the new version, or upgrade directly from the admin panel
