So my brother was the host of our game, my friend wanted it on easy mode instead of peaceful. So he saves and quits the game, everyone is kicked off, then he goes and tries to get back on, gave him a network error. The best solution if you ever get a network error is not to restart your router/modem/PS3, but to just sign out of the PSN and sign back in, after that you should be ready to go.
But if that fails, then I suggest to restart your PS3, or Router/Modem.
But if that fails, then I suggest to restart your PS3, or Router/Modem.
Good luck!