Not appearing on site plugin menus on WPMU / WordPress network

Using the latest version of WordPress (3.5.1) and the plugin. I installed it on my wordpress network, but it doesn’t show up on any of the plugin menus on the site so it can’t actually be activated. I believe it used to work, so no idea why it stopped, maybe it happened with the wordpress update? Would love to use this again since WP total cache doesn’t work at all and pretty much breaks all my sites when activated on one of them.

http://wordpress.org/extend/plugins/w3-total-cache/