Did you update WordPress core and notice you no longer have the text justify or underline button?
The underline and justify buttons are no longer available after the update. According to Andrew Ozz, who primarily works on the TinyMCE editor in WordPress, underlining text causes confusion as readers may interpret it as a link. The justify button was removed because it has uneven browser implementation and often makes text less readable. However, keyboard shortcuts for both buttons will continue to work in 4.7.
To Justify Text Layout | CTRL + SHIFT + J
Underline | CTRL + U
Of course, if you’re using a mac, use the Command button rather than Control.
See a full list of keyboard shortcuts here: https://www.elegantthemes.com/blog/resources/wordpress-keyboard-shortcuts
If you’d like to bring the text-justify button back, there’s a brand new plugin that will do just that: https://wordpress.org/plugins/who-stole-the-text-justify-button/. If you want to re-add both the text-justify and underline, you can use this plugin:
https://wordpress.org/plugins/re-add-underline-justify/, but keep in mind that underlining text that is not a link causes confusion on the web, so it is not recommended.