fail: Microsoft.EntityFrameworkCore.Database.Connection[20004]

      An error occurred using the connection to database 'readdy' on server '.\SQLEXPRESS'.

System.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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)

..

ClientConnectionId:00000000-0000-0000-0000-000000000000

Error Number:-1,State:0,Class:20

fail: Microsoft.EntityFrameworkCore.Database.Connection[20004]

      An error occurred using the connection to database 'readdy' on server '.\SQLEXPRESS'.

System.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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)

   at System.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen()

public static string Connectionstring = "Data Source=.\\SQLEXPRESS;Initial Catalog=readdy;Integrated Security=True;Connect Timeout=60;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=true";   

public static string Connectionstring = "Data Source=.\\SQLEXPRESS;Initial Catalog=readdy;Integrated Security=True;Connect Timeout=60;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=false";