How to solve Error (tinyMCE is not defined) on WordPress admin panel

Sometimes after upgrading your WordPress or plugin, Your Site content editor, the text is not showing and the visual editor is not working.

If you are facing this issue here is a simple solution for you.

1. Press F12 in your keyboard ( Inspect Element )
2.  Select Console option
3. If you are seen the below mentioned error
   ReferenceError: tinymce is not defined
4. If above red mentioned error is there,  you can add the below code on in the wp-config.php

   define('CONCATENATE_SCRIPTS', false);

    

This Code worked for me