我已在 .NET 5.0 上部署了我的 IIS 应用程序，这是一个基本的 API 并具有 context and controllers。 Context 有一个定义好的配置，它有连接字符串：
protected override void Onconfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(@"Server=localhost;Database=flutter;");
optionsBuilder.EnableSensitiveDataLogging();
}
当我在本地托管我的应用程序时一切正常，请求也很好，但是一旦我尝试在我的服务器上调用 API，它就会失败。
调用默认的 API 调用返回 200 OK
500
由于我在调用后检查了 Event Viewer，我发现了一个错误：
Category: microsoft.AspNetCore.Server.IIS.Core.IISHttpServer EventId: 2 SpanId: 73e6b4810067764d TraceId: 2c38235f0fa745438ce6ecdcf1874c44 ParentId: 0000000000000000 RequestId: 80000072-0001-fe00-b63f-84710c7967bb RequestPath: /FlutterAPI/api/Users/5 Connection ID "18302628891539275888",Request ID "80000072-0001-fe00-b63f-84710c7967bb": An unhandled exception was thrown by the application. Exception: microsoft.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: snI_PN11,error: 25 - Connection string is not valid) ---> System.ComponentModel.win32exception (87): The parameter is incorrect. at microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception,Boolean breakConnection,action``1 wrapCloseInaction) at microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj,Boolean callerHasConnectionLock,Boolean asyncClose) at microsoft.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo,SqlInternalConnectionTds connHandler,Boolean ignoresniOpenTimeout,Int64 timerExpire,Boolean encrypt,Boolean trustServerCert,Boolean integratedSecurity,Boolean withFailover,SqlAuthenticationmethod authType) at microsoft.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo,String newPassword,SecureString newSecurePassword,TimeoutTimer timeout,Boolean withFailover) at microsoft.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo,Boolean redirectedUserInstance,SqlConnectionString connectionOptions,SqlCredential credential,TimeoutTimer timeout) at microsoft.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout,Boolean redirectedUserInstance) at microsoft.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity,Object providerInfo,SqlConnectionString userConnectionOptions,SessionData reconnectSessionData,Boolean applyTransientFaultHandling,String accessToken,DbConnectionPool pool) at microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options,DbConnectionPoolKey poolKey,Object poolGroupProviderInfo,DbConnectionPool pool,DbConnection owningConnection,DbConnectionOptions userOptions) at microsoft.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool,DbConnection owningObject,DbConnectionOptions options,DbConnectionOptions userOptions) at microsoft.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject,DbConnectionOptions userOptions,DbConnectionInternal oldConnection) at microsoft.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject,DbConnectionInternal oldConnection) at microsoft.Data.ProviderBase.DbConnectionPool.Trygetconnection(DbConnection owningObject,UInt32 waitForMultipleObjectsTimeout,Boolean allowCreate,Boolean onlyOneCheckConnection,DbConnectionInternal& connection) at microsoft.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen() --- End of stack trace from previous location --- at microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected,CancellationToken cancellationToken) at microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected,CancellationToken cancellationToken) at microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken,Boolean errorsExpected) at microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalcommandparameterObject parameterObject,CancellationToken cancellationToken) at microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable``1.AsyncEnumerator.InitializeReaderAsync(DbContext _,Boolean result,CancellationToken cancellationToken) at microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state,Func``4 operation,Func``4 verifySucceeded,CancellationToken cancellationToken) at microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable``1.AsyncEnumerator.MoveNextAsync() at microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.SingleOrDefaultAsync[tsource](IAsyncEnumerable``1 asyncEnumerable,CancellationToken cancellationToken) at microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.SingleOrDefaultAsync[tsource](IAsyncEnumerable``1 asyncEnumerable,CancellationToken cancellationToken) at FlutterApi.Controllers.UsersController.GetUser(Int64 id) in G:\Projects\flutter_api\ApiFlutter\Controllers\UsersController.cs:line 39 at lambda_method6(Closure,Object ) at microsoft.AspNetCore.Mvc.Infrastructure.actionmethodExecutor.AwaitableObjectResultExecutor.Execute(IactionResultTypeMapper mapper,ObjectMethodExecutor executor,Object controller,Object[] arguments) at microsoft.AspNetCore.Mvc.Infrastructure.ControlleractionInvoker.<InvokeactionmethodAsync>g__Awaited|12_0(ControlleractionInvoker invoker,Valuetask``1 actionResultvalueTask) at microsoft.AspNetCore.Mvc.Infrastructure.ControlleractionInvoker.<InvokeNextactionFilterAsync>g__Awaited|10_0(ControlleractionInvoker invoker,Task lastTask,State next,Scope scope,Object state,Boolean isCompleted) at microsoft.AspNetCore.Mvc.Infrastructure.ControlleractionInvoker.Rethrow(actionExecutedContextSealed context) at microsoft.AspNetCore.Mvc.Infrastructure.ControlleractionInvoker.Next(State& next,Scope& scope,Object& state,Boolean& isCompleted) at microsoft.AspNetCore.Mvc.Infrastructure.ControlleractionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControlleractionInvoker invoker,Boolean isCompleted) at microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker,Boolean isCompleted) at microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker,Task task,IDisposable scope) at microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint,Task requestTask,ILogger logger) at microsoft.AspNetCore.Authorization.Authorizationmiddleware.Invoke(HttpContext context) at microsoft.AspNetCore.Builder.Extensions.UsePathBaseMiddleware.Invoke(HttpContext context) at microsoft.AspNetCore.Server.IIS.Core.IISHttpContextOfT``1.ProcessRequestAsync() ClientConnectionId:00000000-0000-0000-0000-000000000000 Error Number:87,State:0,Class:20
我的 SQL Server 已启动并正在运行
我已将所需用户（在我看来）添加到数据库的登录名
我的 IIS 设置如下所示：
我的应用程序池设置如下
过去几天我一直在网上搜索并尝试不同的方法来解决这个问题，但我就是做不到。我在 IIS 上尝试了不同的设置、不同的方法、不同的服务器，但无法使其工作。急切求助。提前致谢。
编辑 1： 将 SQL Server 更新到最新的 CU 版本