diff --git a/.vs/IoTGateway/v17/.suo b/.vs/IoTGateway/v17/.suo
index 0f07143..5e1b842 100644
Binary files a/.vs/IoTGateway/v17/.suo and b/.vs/IoTGateway/v17/.suo differ
diff --git a/IoTGateway/Startup.cs b/IoTGateway/Startup.cs
index 517cd9c..4ca1a61 100644
--- a/IoTGateway/Startup.cs
+++ b/IoTGateway/Startup.cs
@@ -73,14 +73,14 @@ namespace IoTGateway
 
 
             services.AddHostedService<IoTBackgroundService>();
-            services.AddSingleton<UAService>();
             services.AddSingleton<DeviceService>();
             services.AddSingleton<DrvierService>();
+            services.AddSingleton<UAService>();
             services.AddSingleton<MyMqttClient>();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
-        public void Configure(IApplicationBuilder app, IOptionsMonitor<Configs> configs, UAService uAService, DeviceService deviceService)
+        public void Configure(IApplicationBuilder app, IOptionsMonitor<Configs> configs, DeviceService deviceService)
         {
             IconFontsHelper.GenerateIconFont();
 
diff --git a/Plugins/Plugin/DeviceService.cs b/Plugins/Plugin/DeviceService.cs
index 53d48e4..a03fc6f 100644
--- a/Plugins/Plugin/DeviceService.cs
+++ b/Plugins/Plugin/DeviceService.cs
@@ -30,7 +30,7 @@ namespace Plugin
         private DBTypeEnum DBType = IoTBackgroundService.DBType;
         private Interpreter interpreter = new();
 
-        public DeviceService(IConfiguration ConfigRoot, DrvierService drvierManager, MyMqttClient myMqttClient, IMqttServer mqttServer)
+        public DeviceService(IConfiguration ConfigRoot, DrvierService drvierManager, MyMqttClient myMqttClient, UAService uAService, IMqttServer mqttServer )
         {
             _DrvierManager = drvierManager;
             _MyMqttClient = myMqttClient;
diff --git a/Plugins/Plugin/UA.Server/ReferenceNodeManager.cs b/Plugins/Plugin/UA.Server/ReferenceNodeManager.cs
index a214915..f4e987a 100644
--- a/Plugins/Plugin/UA.Server/ReferenceNodeManager.cs
+++ b/Plugins/Plugin/UA.Server/ReferenceNodeManager.cs
@@ -2777,11 +2777,11 @@ namespace Quickstarts.ReferenceServer
                     #region IoTGatewayDevice
                     using (var DC = new DataContext(IoTBackgroundService.connnectSetting, IoTBackgroundService.DBType))
                     {
-                        foreach (var group in DC.Set<Device>().Where(x => x.DeviceTypeEnum == DeviceTypeEnum.Group).OrderBy(x => x.Index))
+                        foreach (var group in DC.Set<Device>().AsNoTracking().Where(x => x.DeviceTypeEnum == DeviceTypeEnum.Group).OrderBy(x => x.Index).ToList())
                         {
                             FolderState deviceGroupFolder = CreateFolder(root, group.DeviceName, group.DeviceName);
 
-                            foreach (var device in DC.Set<Device>().Where(x => x.ParentId == group.ID).Include(x => x.DeviceVariables).Include(x => x.DeviceConfigs).OrderBy(x => x.Index))
+                            foreach (var device in DC.Set<Device>().AsNoTracking().Where(x => x.ParentId == group.ID).Include(x => x.DeviceVariables).Include(x => x.DeviceConfigs).OrderBy(x => x.Index).ToList())
                             {
                                 FolderState staticFolder = CreateFolder(deviceGroupFolder, device.DeviceName, device.DeviceName);
                                 foreach (var variable in device.DeviceVariables)