Unable to connect to SQL Server database - C # MVC

I am writing an application on ASP.NET MVC.

It took a list of all registered users. To display the list, I decided to use Membership.GetAllUsers() , but I get an exception:

There was a network or instance error while connecting to SQL Server. Server not found or unavailable. Ensure that the instance name is correct and that remote connections are allowed on SQL Server. (provider: SQL Network Interfaces, error: 26 - Error finding the specified server or instance)

Tell me what code is needed? Database localdb , trying to get a list of users through Membership.GetAllUsers() in the controller and pass to the form. There are tables in the database, the connection is normal if you connect via the DatabaseContext db = new DatabaseContext() object DatabaseContext db = new DatabaseContext() . But in this way I can not get the role of users.

 <connectionStrings> <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=aspnet-SoftwareDevelopmentCustom;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnet-SoftwareDevelopmentCustom.mdf" providerName="System.Data.SqlClient" /> </connectionStrings> 

Code:

  using System; using System.Data.Entity; using System.Data.Entity.Infrastructure; using System.Threading; using System.Web.Mvc; using WebMatrix.WebData; using SoftwareDevelopmentCustom.Models; using System.Web.Security; namespace SoftwareDevelopmentCustom.Filters { [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)] public sealed class InitializeSimpleMembershipAttribute : ActionFilterAttribute { private static SimpleMembershipInitializer _initializer; private static object _initializerLock = new object(); private static bool _isInitialized; public override void OnActionExecuting(ActionExecutingContext filterContext) { // Инициализация ASP.NET Simple Membership происходит один раз при старте приложения LazyInitializer.EnsureInitialized(ref _initializer, ref _isInitialized, ref _initializerLock); } private class SimpleMembershipInitializer // определение класса инициализатора { public SimpleMembershipInitializer() { Database.SetInitializer<DatabaseContext>(null); try { using (var context = new DatabaseContext()) { if (!context.Database.Exists()) { // Создание базы данных SimpleMembership без применения миграции Entity Framework ((IObjectContextAdapter)context).ObjectContext.CreateDatabase(); } } // Настройка ASP.NET Simple Membership // 1 параметр - имя строки подключения к базе данных. // 2 параметр - таблица, которая содержит информацию о пользователях // 3 параметр - имя колонки в таблице, которая отвечает за хранение логина // 4 параметр - autoCreateTables автоматическое создание таблиц если они не существуют в базе WebSecurity.InitializeDatabaseConnection("DefaultConnection", "UserProfile", "UserId", "UserName", autoCreateTables: true); SimpleRoleProvider roles = (SimpleRoleProvider)Roles.Provider; SimpleMembershipProvider membership = (SimpleMembershipProvider)Membership.Provider; // Проверка наличия роли Admin if (!roles.RoleExists("Admin")) { roles.CreateRole("Admin"); } // Поиск пользователя с логином admin if (membership.GetUser("admin", false) == null) { membership.CreateUserAndAccount("admin", "qwe123"); // создание пользователя roles.AddUsersToRoles(new[] { "admin" }, new[] { "Admin" }); // установка роли для пользователя } } catch (Exception ex) { throw new InvalidOperationException("The ASP.NET Simple Membership database could not be initialized. For more information, please see http://go.microsoft.com/fwlink/?LinkId=256588", ex); } } } } }