I am getting following error in activity escalation, I checked the sql connection string in evnironment variables, string values and through connectionstring utility and didn't find anything wrong with it.

SetEmailTemplete: Excep -> 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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

Regards,