diff --git a/v2rayN/ServiceLib/Common/JsonUtils.cs b/v2rayN/ServiceLib/Common/JsonUtils.cs
index 4d0f8e71..cf5ec25c 100644
--- a/v2rayN/ServiceLib/Common/JsonUtils.cs
+++ b/v2rayN/ServiceLib/Common/JsonUtils.cs
@@ -70,8 +70,9 @@ namespace ServiceLib.Common
         /// </summary>
         /// <param name="obj"></param>
         /// <param name="indented"></param>
+        /// <param name="nullValue"></param>
         /// <returns></returns>
-        public static string Serialize(object? obj, bool indented = true)
+        public static string Serialize(object? obj, bool indented = true, bool nullValue = false)
         {
             var result = string.Empty;
             try
@@ -82,8 +83,8 @@ namespace ServiceLib.Common
                 }
                 var options = new JsonSerializerOptions
                 {
-                    WriteIndented = indented ? true : false,
-                    DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
+                    WriteIndented = indented,
+                    DefaultIgnoreCondition = nullValue ? JsonIgnoreCondition.Never : JsonIgnoreCondition.WhenWritingNull
                 };
                 result = JsonSerializer.Serialize(obj, options);
             }
@@ -100,38 +101,5 @@ namespace ServiceLib.Common
         /// <param name="obj"></param>
         /// <returns></returns>
         public static JsonNode? SerializeToNode(object? obj) => JsonSerializer.SerializeToNode(obj);
-
-        /// <summary>
-        /// Save as json file
-        /// </summary>
-        /// <param name="obj"></param>
-        /// <param name="filePath"></param>
-        /// <param name="nullValue"></param>
-        /// <returns></returns>
-        public static int ToFile(object? obj, string? filePath, bool nullValue = true)
-        {
-            if (filePath is null)
-            {
-                return -1;
-            }
-            try
-            {
-                using var file = File.Create(filePath);
-
-                var options = new JsonSerializerOptions
-                {
-                    WriteIndented = true,
-                    DefaultIgnoreCondition = nullValue ? JsonIgnoreCondition.Never : JsonIgnoreCondition.WhenWritingNull
-                };
-
-                JsonSerializer.Serialize(file, obj, options);
-                return 0;
-            }
-            catch (Exception ex)
-            {
-                Logging.SaveLog(ex.Message, ex);
-                return -1;
-            }
-        }
     }
 }
\ No newline at end of file
diff --git a/v2rayN/ServiceLib/Handler/ConfigHandler.cs b/v2rayN/ServiceLib/Handler/ConfigHandler.cs
index 8c066868..39d6cb1c 100644
--- a/v2rayN/ServiceLib/Handler/ConfigHandler.cs
+++ b/v2rayN/ServiceLib/Handler/ConfigHandler.cs
@@ -9,7 +9,6 @@ namespace ServiceLib.Handler
     public class ConfigHandler
     {
         private static readonly string _configRes = Global.ConfigFileName;
-        private static readonly object _objLock = new();
 
         #region ConfigHandler
 
@@ -67,7 +66,6 @@ namespace ServiceLib.Handler
             }
 
             config.RoutingBasicItem ??= new();
-
             if (Utils.IsNullOrEmpty(config.RoutingBasicItem.DomainStrategy))
             {
                 config.RoutingBasicItem.DomainStrategy = Global.DomainStrategies.First();//"IPIfNonMatch";
@@ -120,15 +118,6 @@ namespace ServiceLib.Handler
             }
 
             config.ConstItem ??= new ConstItem();
-            if (Utils.IsNotEmpty(config.ConstItem.DefIEProxyExceptions))
-            {
-                config.SystemProxyItem.SystemProxyExceptions = $"{config.ConstItem.DefIEProxyExceptions};{config.SystemProxyItem.SystemProxyExceptions}";
-                config.ConstItem.DefIEProxyExceptions = string.Empty;
-            }
-            if (config.SystemProxyItem.SystemProxyExceptions.IsNullOrEmpty())
-            {
-                config.SystemProxyItem.SystemProxyExceptions = Utils.IsWindows() ? Global.SystemProxyExceptionsWindows : Global.SystemProxyExceptionsLinux;
-            }
 
             config.SpeedTestItem ??= new();
             if (config.SpeedTestItem.SpeedTestTimeout < 10)
@@ -167,6 +156,16 @@ namespace ServiceLib.Handler
             config.WebDavItem ??= new();
             config.CheckUpdateItem ??= new();
 
+            if (Utils.IsNotEmpty(config.ConstItem.DefIEProxyExceptions))
+            {
+                config.SystemProxyItem.SystemProxyExceptions = $"{config.ConstItem.DefIEProxyExceptions};{config.SystemProxyItem.SystemProxyExceptions}";
+                config.ConstItem.DefIEProxyExceptions = string.Empty;
+            }
+            if (config.SystemProxyItem.SystemProxyExceptions.IsNullOrEmpty())
+            {
+                config.SystemProxyItem.SystemProxyExceptions = Utils.IsWindows() ? Global.SystemProxyExceptionsWindows : Global.SystemProxyExceptionsLinux;
+            }
+
             return config;
         }
 
@@ -177,30 +176,26 @@ namespace ServiceLib.Handler
         /// <returns></returns>
         public static async Task<int> SaveConfig(Config config)
         {
-            lock (_objLock)
+            try
             {
-                try
-                {
-                    //save temp file
-                    var resPath = Utils.GetConfigPath(_configRes);
-                    var tempPath = $"{resPath}_temp";
-                    if (JsonUtils.ToFile(config, tempPath) != 0)
-                    {
-                        return -1;
-                    }
+                //save temp file
+                var resPath = Utils.GetConfigPath(_configRes);
+                var tempPath = $"{resPath}_temp";
 
-                    if (File.Exists(resPath))
-                    {
-                        File.Delete(resPath);
-                    }
-                    //rename
-                    File.Move(tempPath, resPath);
-                }
-                catch (Exception ex)
+                var content = JsonUtils.Serialize(config, true, true);
+                if (content.IsNullOrEmpty())
                 {
-                    Logging.SaveLog("ToJsonFile", ex);
                     return -1;
                 }
+                await File.WriteAllTextAsync(tempPath, content);
+
+                //rename
+                File.Move(tempPath, resPath, true);
+            }
+            catch (Exception ex)
+            {
+                Logging.SaveLog("ToJsonFile", ex);
+                return -1;
             }
 
             return 0;
diff --git a/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs b/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs
index 202b5089..e1f26b1b 100644
--- a/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs
+++ b/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs
@@ -409,7 +409,9 @@ namespace ServiceLib.Services.CoreConfig
                     {
                         await GenInbounds(singboxConfig);
                         await GenExperimental(singboxConfig);
-                        JsonUtils.ToFile(singboxConfig, fileName, false);
+
+                        var content = JsonUtils.Serialize(singboxConfig, true);
+                        await File.WriteAllTextAsync(fileName, content);
                     }
                 }
                 else
diff --git a/v2rayN/ServiceLib/ViewModels/MainWindowViewModel.cs b/v2rayN/ServiceLib/ViewModels/MainWindowViewModel.cs
index 9b016ca6..ff680c3d 100644
--- a/v2rayN/ServiceLib/ViewModels/MainWindowViewModel.cs
+++ b/v2rayN/ServiceLib/ViewModels/MainWindowViewModel.cs
@@ -282,16 +282,16 @@ namespace ServiceLib.ViewModels
         {
             try
             {
-                Logging.SaveLog("MyAppExit Begin");
-                await SysProxyHandler.UpdateSysProxy(_config, true);
+                Logging.SaveLog("MyAppExitAsync Begin");
 
                 await ConfigHandler.SaveConfig(_config);
+                await SysProxyHandler.UpdateSysProxy(_config, true);
                 await ProfileExHandler.Instance.SaveTo();
                 await StatisticsHandler.Instance.SaveTo();
                 StatisticsHandler.Instance.Close();
                 await CoreHandler.Instance.CoreStop();
 
-                Logging.SaveLog("MyAppExit End");
+                Logging.SaveLog("MyAppExitAsync End");
             }
             catch { }
             finally