Might be an issue with this plugin and 3.8 relating to menus

After upgrading to WordPress 3.8, an issue appeared with menus on primary site subdomains. The menus disappeared and trying to recreate them doesn’t do anything. The menu page reloads like they are being created, but then when the page refreshes, there is no new menu and the only option is “Create new menu”.

The reason I’m posing this as a possible issue with Networks is that all other plugins are deactivated on the subdomain site using the default theme and the issue is still present. Admins on the WP Multisite thread can’t reproduce the problem. The only active plugin on the entire installation is Networks for WordPress.

http://wordpress.org/plugins/networks-for-wordpress/