If you have gone in to edit one of your pages or posts and seen your editor looks like this:
This means that your site has the newest version of WordPress which is version 5.
Either you updated it or very likely your host updated it automatically for you.
Wordpress 5 comes with Gutenberg, a new editor that is jam packed full of new features for your editor. However you may not want to learn something new right now.
Divi offers a one click solution to remove it for all pages and posts.
First you must ensure Divi is updated to the latest version.
Then go to the Divi menu item ( the left, towards the bottom) -> Theme Options.
In the tabs at the top click Builder -> Advanced.
Then Enable the Classic Editor.
Click "Save Changes".
Then when you return to the page or post editor you will see that it has gone back to the classic editor.
If this was helpful for you please let us know in the comments below.