This is an annoying issue that happened to me lately, whereby the WordPress visual editor had its buttons and icons missing.

I trawled various forums, and got the usual “do a full re-install” etc, or disable and re-enable all plugins blah blah blah.

The solution is here – its elegant, simple and a one-liner: add the below line to your wp-config.php file.

define(‘CONCATENATE_SCRIPTS’, false );