Sitecore Tackled

This error message caught my eye on xConnect in Sitecore 9.3, which looked like this.

"[Error] Sitecore.XConnect.Operations.GetEntityOperation`1[Sitecore.XConnect.DeviceProfile]: Sitecore.Xdb.Collection.Failures.DataProviderException: 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) ---> System.Data.SqlClient.SqlException: 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) ---> System.ComponentModel.Win32Exception: The system cannot find the file specified"

This issue was because of Xdb had wrong ServerName in the [*.Collection.ShardMapManager] database.

The database and table “[*.Collection.ShardMapManager].[__ShardManagement].[ShardsGlobal]” that contains [ServerName] and [DatabaseName] columns. Replace with your ServerName and hopefully this will be the issue in your case.

Hope this helps if you get a similar error.