Nov 28, 2023 · I am working on a .NET 8 application using Entity Framework Core 8 and targeting SQL Server 2022 (Express Edition). Despite having a correct connection string in my appsettings.json, I am encountering an InvalidOperationException stating that the ConnectionString property has not been initialized.

May 16, 2019 · 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.

Aug 15, 2019 · 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.

Jun 10, 2021 · 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.

Dec 5, 2023 · This error occurs because SSL is used during the database login verification phase, causing the authentication to fail. Minimum allowed ssl version and SQL Server database …

May 13, 2019 · Open() method in SqlConnection throws SqlException when connecting to named instance of SQL Server. This only happen when the client is a .Net Core app. It connects correctly for .Net Framework application.

Dec 22, 2021 · I'm trying to connect to SQL Server Express LocalDB from .NET Core 6 on Windows 11 ARM. If I use a connection string that refers to it using the instance name "Data Source= (localdb)\MSSQLLocalDB", it fails with the exception below. If I connect to it using a named pipe, it works.

Apr 17, 2023 · Based on the error message you received, it seems that the application is unable to authenticate the NT Authority\System account to access the SQL LocalDB. Verify that the connection string used by your application is correct and points to …

Jul 16, 2019 · Starting in 3.0, the ASP.NET Core shared framework doesn't include EF Core or any EF Core data providers. So you just need to add an explicit reference to the EF Core database provider you are using ( SQL Server ) and the UseSqlServer extension method should become available again.

Jun 25, 2024 · 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.