Problem:

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: TCP Provider, error: 0 – No connection could be made because the target machine actively refused it.)

Solution:

SQL Estate Manager cannot connect to your instance due to one of the following problems:

• TCP/IP or Named Pipes protocols are disabled
• Remote Connections are not enabled
• The firewall is blocking access to the SQL Server, check firewall configuration for the port you are using

For more information, refer to SQL Server Configuration Prerequisites.