If one of the servers in a view connection server replicated environment lose the ability to communicate with the other servers for more than a couple of hours then the view loses the ability to refresh/recompose the pools.
Try restarting the connection server service or restarting the server that had the communication issue. If that does not work bounce all of the replicated servers as well. You may also have to restart View Composer Service on your Virtual Center Server aftwards. If the View Composer Service locks up while trying to restart it you will need to reboot your Virtual Center Server.