UnetServer.cs

private void OnClientAddPlayer(NetworkMessage netmsg) {
        var msg = netmsg.ReadMessage<AddPlayerMessage>();
        Debug.Log("Spawning object for player: " + msg.playerControllerId);
        
        /* First, create instance and spawn it */
        
        var instance = (GameObject)Instantiate(_playerPrefab, Vector3.zero, Quaternion.identity);
        NetworkServer.AddPlayerForConnection(netmsg.conn, instance, msg.playerControllerId);
        
        /* Then add role-specific components and resolve dependencies, if prefab needs it */

        var simulator = instance.GetComponent<PlayerSimulation>();
        simulator.GameClockFixed = _gameClockFixed;

        var network = instance.GetComponent<PlayerNetwork>();

        var server = instance.AddComponent<PlayerServer>();
        server.GameClockFixed = _gameClockFixed;
        server.GameClock = _gameClock;
        server.Simulation = simulator;
        server.Network = network;

        var dedicated = instance.AddComponent<PlayerDedicated>();
        dedicated.Network = network;
        dedicated.Server = server;

        instance.name += "_server";
        LayerUtil.SetLayerRecursively(instance.transform, LayerMask.NameToLayer("Server"));
    }