The theme editor in WordPress is a nice little feature which allows administrators to, via the brower, edit the theme files available to the WordPress installation.
For security reasons however, this feature is not part of WordPress, the risk being that if the editor is available, then someone with access to it might maliciously change code.
If such a security risk is not a problem though and you want to enable the theme editor, you must do two things:
2. Edit line # 401 of the file ‘/wp-admin/includes/mu.php’ by commenting out or deleting the line:
unset( $submenu['themes.php'][10] );
1. the file theme-editor.php is not included with Wordpres MU. So get a copy of it from a standard WordPress source (it is under ‘/wp-admin/’) and place it under the ‘/wp-admin/’ folder of your WordPress MU installation.
Originally Posted at: sjdalf Blog