Error with community plugin

Hello,

I'm having a problem with the community plugin. I activated the community plugin on the network. I activated the avatar plugin on the network.
Now I go to wp-admin/ and I reload the page. I see the community link in the menu. I click it and I have this error :

The requested URL /wp-admin/communities.php was not found on this server.
The URL is : /wp-admin/communities.php