diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo.Abp.AspNetCore.Components.Web.csproj b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo.Abp.AspNetCore.Components.Web.csproj
index bc975f9f92..7f89d1c254 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo.Abp.AspNetCore.Components.Web.csproj
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo.Abp.AspNetCore.Components.Web.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFramework>net7.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <RootNamespace />
   </PropertyGroup>
 
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorClientHttpMessageHandler.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorClientHttpMessageHandler.cs
index eb8bee99bd..c92c121628 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorClientHttpMessageHandler.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorClientHttpMessageHandler.cs
@@ -82,7 +82,7 @@ public class AbpBlazorClientHttpMessageHandler : DelegatingHandler, ITransientDe
 
         var selfUri = new Uri(_navigationManager.Uri);
 
-        if (request.RequestUri.Host != selfUri.Host || request.RequestUri.Port != selfUri.Port)
+        if (request.RequestUri!.Host != selfUri.Host || request.RequestUri.Port != selfUri.Port)
         {
             return;
         }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorMessageLocalizerHelper.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorMessageLocalizerHelper.cs
index 52efbc6d11..dc0a2182cb 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorMessageLocalizerHelper.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/AbpBlazorMessageLocalizerHelper.cs
@@ -14,12 +14,12 @@ public class AbpBlazorMessageLocalizerHelper<T>
         this.stringLocalizer = stringLocalizer;
     }
 
-    public string Localize(string message, [CanBeNull] IEnumerable<string> arguments)
+    public string Localize(string message, IEnumerable<string>? arguments)
     {
         try
         {
             return arguments?.Count() > 0
-                ? stringLocalizer[message, LocalizeMessageArguments(arguments)?.ToArray()]
+                ? stringLocalizer[message, LocalizeMessageArguments(arguments)?.ToArray()!]
                 : stringLocalizer[message];
         }
         catch
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieOptions.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieOptions.cs
index 283f665642..d8a5ec3a1a 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieOptions.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieOptions.cs
@@ -5,6 +5,6 @@ namespace Volo.Abp.AspNetCore.Components.Web;
 public class CookieOptions
 {
     public DateTimeOffset? ExpireDate { get; set; }
-    public string Path { get; set; }
+    public string? Path { get; set; }
     public bool Secure { get; set; }
 }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieService.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieService.cs
index 1b61acb459..a3868d5b2e 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieService.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/CookieService.cs
@@ -14,7 +14,7 @@ public class CookieService : ICookieService, ITransientDependency
         JsRuntime = jsRuntime;
     }
 
-    public async ValueTask SetAsync(string key, string value, CookieOptions options)
+    public async ValueTask SetAsync(string key, string value, CookieOptions? options)
     {
         await JsRuntime.InvokeVoidAsync("abp.utils.setCookieValue", key, value, options?.ExpireDate?.ToString("r"), options?.Path, options?.Secure);
     }
@@ -24,7 +24,7 @@ public class CookieService : ICookieService, ITransientDependency
         return await JsRuntime.InvokeAsync<string>("abp.utils.getCookieValue", key);
     }
 
-    public async ValueTask DeleteAsync(string key, string path = null)
+    public async ValueTask DeleteAsync(string key, string? path = null)
     {
         await JsRuntime.InvokeVoidAsync("abp.utils.deleteCookie", key);
     }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DefaultServerUrlProvider.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DefaultServerUrlProvider.cs
index 281ee3cd73..aae5f1f98b 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DefaultServerUrlProvider.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DefaultServerUrlProvider.cs
@@ -5,7 +5,7 @@ namespace Volo.Abp.AspNetCore.Components.Web;
 
 public class DefaultServerUrlProvider : IServerUrlProvider, ISingletonDependency
 {
-    public Task<string> GetBaseUrlAsync(string remoteServiceName = null)
+    public Task<string> GetBaseUrlAsync(string? remoteServiceName = null)
     {
         return Task.FromResult("/");
     }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DependencyInjection/ComponentsClientScopeServiceProviderAccessor.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DependencyInjection/ComponentsClientScopeServiceProviderAccessor.cs
index f5e07865a7..2311a2c9f9 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DependencyInjection/ComponentsClientScopeServiceProviderAccessor.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/DependencyInjection/ComponentsClientScopeServiceProviderAccessor.cs
@@ -7,5 +7,5 @@ public class ComponentsClientScopeServiceProviderAccessor :
     IClientScopeServiceProviderAccessor,
     ISingletonDependency
 {
-    public IServiceProvider ServiceProvider { get; set; }
+    public IServiceProvider ServiceProvider { get; set; } = default!;
 }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLogger.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLogger.cs
index cf66f107a0..ba56233ec5 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLogger.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLogger.cs
@@ -8,7 +8,7 @@ namespace Volo.Abp.AspNetCore.Components.Web.ExceptionHandling;
 public class AbpExceptionHandlingLogger : ILogger
 {
     private readonly IServiceCollection _serviceCollection;
-    private IUserExceptionInformer _userExceptionInformer;
+    private IUserExceptionInformer? _userExceptionInformer;
 
     public AbpExceptionHandlingLogger(IServiceCollection serviceCollection)
     {
@@ -19,7 +19,7 @@ public class AbpExceptionHandlingLogger : ILogger
         LogLevel logLevel,
         EventId eventId,
         TState state,
-        Exception exception,
+        Exception? exception,
         Func<TState, Exception, string> formatter)
     {
         if (exception == null)
@@ -58,7 +58,7 @@ public class AbpExceptionHandlingLogger : ILogger
         return logLevel == LogLevel.Critical || logLevel == LogLevel.Error;
     }
 
-    public virtual IDisposable BeginScope<TState>(TState state)
+    public virtual IDisposable? BeginScope<TState>(TState state) where TState : notnull
     {
         return NullDisposable.Instance;
     }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLoggerProvider.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLoggerProvider.cs
index 3f895502fa..d13fd5a751 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLoggerProvider.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/AbpExceptionHandlingLoggerProvider.cs
@@ -5,7 +5,7 @@ namespace Volo.Abp.AspNetCore.Components.Web.ExceptionHandling;
 
 public class AbpExceptionHandlingLoggerProvider : ILoggerProvider
 {
-    private AbpExceptionHandlingLogger _logger;
+    private AbpExceptionHandlingLogger? _logger;
     private static readonly object SyncObj = new object();
     private readonly IServiceCollection _serviceCollection;
 
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/UserExceptionInformer.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/UserExceptionInformer.cs
index 0f0da11bdf..6773e4ff37 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/UserExceptionInformer.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ExceptionHandling/UserExceptionInformer.cs
@@ -39,11 +39,11 @@ public class UserExceptionInformer : IUserExceptionInformer, IScopedDependency
 
         if (errorInfo.Details.IsNullOrEmpty())
         {
-            MessageService.Error(errorInfo.Message);
+            MessageService.Error(errorInfo.Message!);
         }
         else
         {
-            MessageService.Error(errorInfo.Details, errorInfo.Message);
+            MessageService.Error(errorInfo.Details!, errorInfo.Message);
         }
     }
 
@@ -53,11 +53,11 @@ public class UserExceptionInformer : IUserExceptionInformer, IScopedDependency
 
         if (errorInfo.Details.IsNullOrEmpty())
         {
-            await MessageService.Error(errorInfo.Message);
+            await MessageService.Error(errorInfo.Message!);
         }
         else
         {
-            await MessageService.Error(errorInfo.Details, errorInfo.Message);
+            await MessageService.Error(errorInfo.Details!, errorInfo.Message);
         }
     }
 
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityAction.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityAction.cs
index 837eb2c96a..56bcf3d543 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityAction.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityAction.cs
@@ -5,15 +5,15 @@ namespace Volo.Abp.AspNetCore.Components.Web.Extensibility.EntityActions;
 
 public class EntityAction : IEquatable<EntityAction>
 {
-    public string Text { get; set; }
-    public Func<object, Task> Clicked { get; set; }
-    public Func<object, string> ConfirmationMessage { get; set; }
+    public string Text { get; set; } = default!;
+    public Func<object, Task> Clicked { get; set; } = default!;
+    public Func<object, string>? ConfirmationMessage { get; set; }
     public bool Primary { get; set; }
-    public object Color { get; set; }
-    public string Icon { get; set; }
-    public Func<object, bool> Visible { get; set; }
+    public object? Color { get; set; }
+    public string? Icon { get; set; }
+    public Func<object, bool>? Visible { get; set; }
     public bool Disabled { get; set; }
-    public bool Equals(EntityAction other)
+    public bool Equals(EntityAction? other)
     {
         return string.Equals(Text, other?.Text, StringComparison.OrdinalIgnoreCase);
     }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityActionDictionary.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityActionDictionary.cs
index 0781870b69..8f638baff6 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityActionDictionary.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/EntityActions/EntityActionDictionary.cs
@@ -6,6 +6,6 @@ public class EntityActionDictionary : Dictionary<string, List<EntityAction>>
 {
     public List<EntityAction> Get<T>()
     {
-        return this.GetOrAdd(typeof(T).FullName, () => new List<EntityAction>());
+        return this.GetOrAdd(typeof(T).FullName!, () => new List<EntityAction>());
     }
 }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumn.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumn.cs
index aa48ad633b..efd1d9320b 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumn.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumn.cs
@@ -8,23 +8,20 @@ namespace Volo.Abp.AspNetCore.Components.Web.Extensibility.TableColumns;
 
 public class TableColumn
 {
-    public string Title { get; set; }
-    public string Data { get; set; }
+    public string Title { get; set; } = default!;
+    public string Data { get; set; } = default!;
 
-    public string PropertyName { get; set; }
+    public string PropertyName { get; set; } = default!;
 
-    [CanBeNull]
-    public string DisplayFormat { get; set; }
+    public string? DisplayFormat { get; set; }
 
     public IFormatProvider DisplayFormatProvider { get; set; } = CultureInfo.CurrentCulture;
 
-    [CanBeNull]
-    public Type Component { get; set; }
+    public Type? Component { get; set; }
 
     public List<EntityAction> Actions { get; set; }
 
-    [CanBeNull]
-    public Func<object, string> ValueConverter { get; set; }
+    public Func<object, string>? ValueConverter { get; set; }
 
     public bool Sortable { get; set; }
 
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumnDictionary.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumnDictionary.cs
index 7eda70177c..67616eb061 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumnDictionary.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Extensibility/TableColumns/TableColumnDictionary.cs
@@ -6,6 +6,6 @@ public class TableColumnDictionary : Dictionary<string, List<TableColumn>>
 {
     public List<TableColumn> Get<T>()
     {
-        return this.GetOrAdd(typeof(T).FullName, () => new List<TableColumn>());
+        return this.GetOrAdd(typeof(T).FullName!, () => new List<TableColumn>());
     }
 }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ICookieService.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ICookieService.cs
index afb124644e..393088fd6c 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ICookieService.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/ICookieService.cs
@@ -4,7 +4,7 @@ namespace Volo.Abp.AspNetCore.Components.Web;
 
 public interface ICookieService
 {
-    public ValueTask SetAsync(string key, string value, CookieOptions options = null);
+    public ValueTask SetAsync(string key, string value, CookieOptions? options = null);
     public ValueTask<string> GetAsync(string key);
-    public ValueTask DeleteAsync(string key, string path = null);
+    public ValueTask DeleteAsync(string key, string? path = null);
 }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/IServerUrlProvider.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/IServerUrlProvider.cs
index f5266a9f18..76c261ea80 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/IServerUrlProvider.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/IServerUrlProvider.cs
@@ -4,5 +4,5 @@ namespace Volo.Abp.AspNetCore.Components.Web;
 
 public interface IServerUrlProvider
 {
-    Task<string> GetBaseUrlAsync(string remoteServiceName = null);
+    Task<string> GetBaseUrlAsync(string? remoteServiceName = null);
 }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Messages/SimpleUiMessageService.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Messages/SimpleUiMessageService.cs
index 647be65b41..91c1648cd2 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Messages/SimpleUiMessageService.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Messages/SimpleUiMessageService.cs
@@ -15,27 +15,27 @@ public class SimpleUiMessageService : IUiMessageService, ITransientDependency
         JsRuntime = jsRuntime;
     }
 
-    public async Task Info(string message, string title = null, Action<UiMessageOptions> options = null)
+    public async Task Info(string message, string? title = null, Action<UiMessageOptions>? options = null)
     {
         await JsRuntime.InvokeVoidAsync("alert", message);
     }
 
-    public async Task Success(string message, string title = null, Action<UiMessageOptions> options = null)
+    public async Task Success(string message, string? title = null, Action<UiMessageOptions>? options = null)
     {
         await JsRuntime.InvokeVoidAsync("alert", message);
     }
 
-    public async Task Warn(string message, string title = null, Action<UiMessageOptions> options = null)
+    public async Task Warn(string message, string? title = null, Action<UiMessageOptions>? options = null)
     {
         await JsRuntime.InvokeVoidAsync("alert", message);
     }
 
-    public async Task Error(string message, string title = null, Action<UiMessageOptions> options = null)
+    public async Task Error(string message, string? title = null, Action<UiMessageOptions>? options = null)
     {
         await JsRuntime.InvokeVoidAsync("alert", message);
     }
 
-    public async Task<bool> Confirm(string message, string title = null, Action<UiMessageOptions> options = null)
+    public async Task<bool> Confirm(string message, string? title = null, Action<UiMessageOptions>? options = null)
     {
         return await JsRuntime.InvokeAsync<bool>("confirm", message);
     }
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/AbpComponentsClaimsCache.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/AbpComponentsClaimsCache.cs
index 7473387f83..74cbd37e29 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/AbpComponentsClaimsCache.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/AbpComponentsClaimsCache.cs
@@ -9,10 +9,9 @@ namespace Volo.Abp.AspNetCore.Components.Web.Security;
 
 public class AbpComponentsClaimsCache : IScopedDependency
 {
-    public ClaimsPrincipal Principal { get; private set; }
+    public ClaimsPrincipal Principal { get; private set; } = default!;
 
-    [CanBeNull]
-    private readonly AuthenticationStateProvider _authenticationStateProvider;
+    private readonly AuthenticationStateProvider? _authenticationStateProvider;
 
     public AbpComponentsClaimsCache(
         IClientScopeServiceProviderAccessor serviceProviderAccessor)
diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/ApplicationConfigurationChangedService.cs b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/ApplicationConfigurationChangedService.cs
index 9803a7991d..15aeb7eedb 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/ApplicationConfigurationChangedService.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web/Volo/Abp/AspNetCore/Components/Web/Security/ApplicationConfigurationChangedService.cs
@@ -6,7 +6,7 @@ public delegate void ApplicationConfigurationChangedHandler();
 
 public class ApplicationConfigurationChangedService : IScopedDependency
 {
-    public event ApplicationConfigurationChangedHandler Changed;
+    public event ApplicationConfigurationChangedHandler Changed = default!;
 
     public void NotifyChanged()
     {