I just upgraded kcadp.org to WordPress 3.5. After the upgrade, the WYSIWYG editor disappeared (in both Firefox and Safari) and I'm not able to add text to the body fields for either a page or post. I verified the "disable visual editor" checkbox on the profile page is unchecked. This problem did not occur with any of the five other WordPress sites I oversee. I did have this problem with another site in the past, I was able to get it working by adding
define( 'CONCATENATE_SCRIPTS', false );
near the top of wp-config.php. I can't find that file anymore though.
How do I get it back?