'log4net.Core.LoggerManager'的类型初始值设定项引发了异常

Question

我在我的UWP项目中使用eSignLive。在过去的几个星期，它工作得很好。但现在它在

上抛出异常

eslClient = new EslClient（API_KEY，API_URL）;

例外：'log4net.Core.LoggerManager'的类型初始值设定项引发异常。

我的代码如下

<Button Content="Button" HorizontalAlignment="Left" Height="200"    Width="200" Tapped="Button_Tapped" VerticalAlignment="Top"/>


private string API_URL = string.Empty;
private string API_KEY = string.Empty;
private static EslClient eslClient;

private void Button_Tapped(object sender, Windows.UI.Xaml.Input.TappedRoutedEventArgs e)
    {
        try
        {
           API_URL = "https://sandbox.esignlive.com/api";
            API_KEY = "M2JPbjpXQVlOmE3N3VIenhJVQ==";

            eslClient = new EslClient(API_KEY, API_URL);

        }
        catch (Exception ex)
        {
         }
    }

任何帮助将不胜感激。 感谢