This is my first post so please be kind. I am a WordPress n00b.
After a bit of mucking around I have configured Multi site to work and everything was going fine until i tried to Network activate some Plug-ins from Network-Admin, Plugins. Now the plugins are fine on the Main site but the second site plugins are not showing up. This message shows when i go to the plugins on the second site "The plugin facebook-plugin-pro/fbConnectCore.php has been deactivated due to an error: Plugin file does not exist".
I have three messages like that for various plugins but i think it is all related and not just down to the plugin.