unable to view sharepoint list created through BCS external list from designer

Question

IM using BCS connecting to local DB from SharePoint site in designer creating external lists but i'm facing error as below :

Cannot connect to the LobSystem (External System). Reason: '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: 52 - Unable to locate Database runtime installation. Verify that SQL Server Express is properly installed and the Local Database Runtime Feature is enabled.)'

Answer 1

This error usually occurs because of a connection issue between your External List and its External Content Type Data Source (DB Server).

Some points to trace your issue:

• Make sure that the DB server is up and running.
• Make sure that the Db server is reachable from app server using Ping cmdlet.
• Make sure that you are able to connect to the SQL server instance from App Server check HOW TO CHECK SQL SERVER INSTANCE CONNECTIVITY FROM THE APPLICATION SERVER TO DATABASE SERVER FOR A SPECIFIC USER WITHOUT USING SQL SERVER MANAGEMENT STUDIO

• Make sure that the SQL server services are running.

• Check with your system admin to the firewall status.

• Reconfigure the external content type data source again.