In our previous tutorial How to Disable Theme/Plugin File Editors in WordPress Dashboard we saw How to Disable File Editing From WordPress Dashboard however that was not a definite solution to the problem (like prohibiting the administrator level users from modifying WordPress) as the Administrator level users can still Add,Delete the Plugins and themes from the WordPress Dashboard. However with this solution you can restrict them from adding or deleting the Plugins and Theme from the WordPress dashboard.
One more thing before proceeding this will also prohibit users from editing WordPress theme and Plugin files.
Disable Theme/Plugin Update,Install,Delete from WordPress Dashboard
1.Open your WordPress Directory.
2.Open the wp-config.php file and add the below piece of code in at an appropriate place.
Note-After Adding the above code,you can’t Install,Delete and Update themes and plugins from WordPress Dashboard,Yes Remember you can’t even Update from WordPress Dashboard as you will not see the Update option anymore.
3.Save the PHP file.
To add and delete themes and Plugins you will have to it from your directory manually.