To enable old WordPress editor instead of new WordPress 5 block editor
With the new update of WordPress 5, the old post editor is replaced with new block editor. Which most people don’t like.
In order to switch back to the old one, here is a simple trick.
On left side menu, click Appearance and Select Editor:
On the right side, you need to select your current theme (which in most cases is already selected).
Then select Theme Function from Theme Files.
You will see the script of Theme Functions in the mid.
Add a line at the end of the script:
add_filter('use_block_editor_for_post', '__return_false');
and click Update.
You will get back your old WordPress editor.
THANK YOU SO MUCH!!!