C# WCF服务服务器引发异常，无法访问已释放的对象

因此，我的服务是两个wcf客户端之间的简单聊天应用程序。事件回调在我调用事件时起作用。在我关闭客户端并再次运行它，并再次编写消息（调用事件）后，它会向我抛出异常：

An exception of type 'System.ObjectDisposedException' occurred in
RussianRouletteServiceLibrary.dll but was not handled in user code

Additional information: Cannot access a disposed object.

我的服务回调的代码如下所示：

    private static Action<User, UMessage> gameChat = delegate { };

    public void Play()
    {
        IGameCallback subscriber =
                   OperationContext.Current.GetCallbackChannel<IGameCallback>();
        gameChat += subscriber.PlayerSentMessage;
    }

每次我

.ChannelFactory.Close（）时都会出现此错误
.Close（）正在发生关闭表单事件时客户端

有没有人知道如何解决这个问题并愿意分享他的知识？
提前谢谢你

编辑#1
这是客户端打开时的代码：

    ConcurrencyMode.Multiple,
    UseSynchronizationContext = false)]
    public partial class GameForm : Form, IGameCallback
    {
    #region IGame Callbacks
    public void PlayerSentMessage(User user, UMessage message)
    {
        string nickname = user.NickName == clientUser.NickName ? "You" : user.NickName;
        this.Invoke(new MethodInvoker(() => lb_ChatBox.Items.Add(nickname + " : " + message.MessageContent)));
     }
    #endregion

    private GameClient _gameClient = null;
    private InstanceContext _instance = null;
    private User clientUser = new User(){ Email = "zigm4s@gmail.com", Id = 0, FirstName = "Zigmas", LastName = "Slusnys", NickName = "Ziggy", Password = "test123"};




    public GameForm()
    {
        string state;


        if (_gameClient != null)
        {
            MessageBox.Show("nelygu null");
            MessageBox.Show(_gameClient.State.ToString());
            //_gameClient = new GameClient(new InstanceContext(this));
        }
        else
        {

            _gameClient = new GameClient(new InstanceContext(this));
            MessageBox.Show(_gameClient.State.ToString());
        }

        InitializeComponent();

        try
        {
            _gameClient.Open();
            _gameClient.Play();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }

    }

此时客户端窗体将关闭

    private void GameForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        try {
            if (_gameClient.State != System.ServiceModel.CommunicationState.Faulted)
            {
                MessageBox.Show("Closing client");
                _gameClient.ChannelFactory.Close();
                _gameClient.Close();
            }
            else
            {
                MessageBox.Show("Aborting client");
                _gameClient.Abort();
            }
            }
        catch(Exception ex)
        { MessageBox.Show(ex.ToString());}
    }

编辑#2
我发现了错误，在服务端，我的代理是静态的。如果不是静态的，它不会抛出此错误。
能否显示有关如何关闭客户端然后创建新客户端的更多代码？我添加了客户端打开和关闭，您认为我关闭客户端的方式有问题吗？
    private void GameForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        try {
            if (_gameClient.State != System.ServiceModel.CommunicationState.Faulted)
            {
                MessageBox.Show("Closing client");
                _gameClient.ChannelFactory.Close();
                _gameClient.Close();
            }
            else
            {
                MessageBox.Show("Aborting client");
                _gameClient.Abort();
            }
            }
        catch(Exception ex)
        { MessageBox.Show(ex.ToString());}
    }