diff --git a/Flawless.Client/UIHelper.cs b/Flawless.Client/UIHelper.cs
index 9583e51..b510bcf 100644
--- a/Flawless.Client/UIHelper.cs
+++ b/Flawless.Client/UIHelper.cs
@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using System.Reactive.Disposables;
 using System.Threading.Tasks;
 using Avalonia.Controls.ApplicationLifetimes;
@@ -6,6 +7,8 @@ using Avalonia.Controls.Notifications;
 using Avalonia.VisualTree;
 using Flawless.Client.ViewModels.ModalBox;
 using Flawless.Client.Views.ModalBox;
+using Newtonsoft.Json;
+using Refit;
 using Ursa.Controls;
 using Notification = Ursa.Controls.Notification;
 using WindowNotificationManager = Ursa.Controls.WindowNotificationManager;
@@ -14,12 +17,21 @@ namespace Flawless.Client;
 
 public static class UIHelper
 {
+    [Serializable]
+    private struct FailureData
+    {
+        public string? Message;
+
+        public string? Failure;
+    }
     
     private static WindowNotificationManager _notificationManager = null!;
     
     private static LoadingContainer _loadingContainer = null!;
 
     private static int _loadingReferenceCount = 0;
+    
+    private static JsonSerializer _serializer = JsonSerializer.Create();
 
     public static WindowNotificationManager Notify
     {
@@ -71,18 +83,47 @@ public static class UIHelper
     
 
 
-    public static void NotifyError(Exception ex)
+    public static void NotifyError(Exception ex, string? rewriteTitle = null)
     {
         try
         {
-            var content = ex.ToString();
+            Console.Error.Write(ex);
+            
+            string content;
+            string title;
+            if (ex is ApiException aex)
+            {
+                title = rewriteTitle ?? $"API Error: {aex.StatusCode.ToString()}";
+                if (string.IsNullOrEmpty(aex.Content))
+                {
+                    content = aex.Message;
+                }
+                else
+                {
+                    try
+                    {
+                        var result = _serializer.Deserialize<FailureData>(new JsonTextReader(new StringReader(aex.Content)));
+                        content = result.Message ?? aex.Message;
+                    }
+                    catch (Exception _)
+                    {
+                        content = aex.Content;
+                    }
+                }
+            }
+            else
+            {
+                title = rewriteTitle ?? $"Error: {ex.GetType().Name}";
+                content = ex.ToString();
+            }
+            
             if (content.Length > 100) content = content.Substring(0, 100) + "...";
-            var nf = new Notification(ex.GetType().Name, content, NotificationType.Error);
+            var nf = new Notification(title, content, NotificationType.Error);
             Notify.Show(nf);
         }
         catch (Exception e)
         {
-            Console.WriteLine("Can not notify error to users: " + e);
+            Console.Error.Write("Can not notify error to users: " + e);
         }
     }
     
diff --git a/Flawless.Client/Views/SettingView.axaml b/Flawless.Client/Views/SettingView.axaml
index e1552d2..a0eae50 100644
--- a/Flawless.Client/Views/SettingView.axaml
+++ b/Flawless.Client/Views/SettingView.axaml
@@ -81,8 +81,20 @@
                 </ScrollViewer>
             </TabItem>
             <TabItem IsVisible="{Binding LoginUser.IsAdmin}" Header="Users">
-                <Grid Margin="10">
-                    <DataGrid ItemsSource="{Binding Users}" AutoGenerateColumns="False">
+                <Grid RowDefinitions="Auto, *" Margin="10">
+                    
+                    <StackPanel Orientation="Horizontal">
+                        <Button Content="Refresh Users" 
+                                VerticalAlignment="Bottom" 
+                                HorizontalAlignment="Right"
+                                Command="{Binding CreateUserCommand}"/>
+                        <Button Content="Add Users" 
+                                VerticalAlignment="Bottom" 
+                                HorizontalAlignment="Right"
+                                Command="{Binding CreateUserCommand}"/>
+                    </StackPanel>
+                    
+                    <DataGrid Grid.Row="1" ItemsSource="{Binding Users}" AutoGenerateColumns="False">
                         <DataGrid.Columns>
                             <DataGridTextColumn Header="Username" Binding="{Binding Username}" Width="*"/>
                             
@@ -140,11 +152,6 @@
                         </DataGrid.Columns>
                     </DataGrid>
                     
-                    <!-- 添加用户按钮 -->
-                    <Button Content="添加用户" 
-                          VerticalAlignment="Bottom" 
-                          HorizontalAlignment="Right"
-                          Command="{Binding CreateUserCommand}"/>
                 </Grid>
             </TabItem>
             <TabItem IsVisible="{Binding LoginUser.IsAdmin}" Header="Logfile">
diff --git a/Flawless.Server/appsettings.Development.json b/Flawless.Server/appsettings.Development.json
index 1ad22a3..1e8ba76 100644
--- a/Flawless.Server/appsettings.Development.json
+++ b/Flawless.Server/appsettings.Development.json
@@ -7,7 +7,7 @@
   },
   "AllowedHosts": "*",
   "ConnectionStrings": {
-    "CoreDb": "Server=192.168.10.172;Port=5432;User Id=postgres;Password=postgres;Database=flawless"
+    "CoreDb": "Server=localhost;Port=5432;User Id=postgres;Database=flawless"
   },
   "LocalStoragePath": "./data/development",
   "User": {
diff --git a/Flawless.Server/appsettings.json b/Flawless.Server/appsettings.json
index 1ad22a3..1e8ba76 100644
--- a/Flawless.Server/appsettings.json
+++ b/Flawless.Server/appsettings.json
@@ -7,7 +7,7 @@
   },
   "AllowedHosts": "*",
   "ConnectionStrings": {
-    "CoreDb": "Server=192.168.10.172;Port=5432;User Id=postgres;Password=postgres;Database=flawless"
+    "CoreDb": "Server=localhost;Port=5432;User Id=postgres;Database=flawless"
   },
   "LocalStoragePath": "./data/development",
   "User": {