diff --git a/shadowsocks-csharp/Model/Configuration.cs b/shadowsocks-csharp/Model/Configuration.cs
index b0bec8ad..23523416 100644
--- a/shadowsocks-csharp/Model/Configuration.cs
+++ b/shadowsocks-csharp/Model/Configuration.cs
@@ -43,7 +43,8 @@ namespace Shadowsocks.Model
 
         [JsonIgnore]
         public string localHost => GetLocalHost();
-        private string GetLocalHost() {
+        private string GetLocalHost()
+        {
             return isIPv6Enabled ? "[::1]" : "127.0.0.1";
         }
         public Server GetCurrentServer()
@@ -82,9 +83,9 @@ namespace Shadowsocks.Model
                 string configContent = File.ReadAllText(CONFIG_FILE);
                 Configuration config = JsonConvert.DeserializeObject<Configuration>(configContent);
                 config.isDefault = false;
-                if (UpdateChecker.Asset.CompareVersion(UpdateChecker.Version, config.version) > 0)
+                if (UpdateChecker.Asset.CompareVersion(UpdateChecker.Version, config.version ?? "0") > 0)
                 {
-                    config.updated = true; 
+                    config.updated = true;
                 }
 
                 if (config.configs == null)
@@ -101,7 +102,8 @@ namespace Shadowsocks.Model
                     config.proxy = new ProxyConfig();
                 if (config.hotkey == null)
                     config.hotkey = new HotkeyConfig();
-                if (!System.Net.Sockets.Socket.OSSupportsIPv6) {
+                if (!System.Net.Sockets.Socket.OSSupportsIPv6)
+                {
                     config.isIPv6Enabled = false; // disable IPv6 if os not support
                 }
                 //TODO if remote host(server) do not support IPv6 (or DNS resolve AAAA TYPE record) disable IPv6?