Configure the SQL alias %SqlInstance; on the SharePoint front-end web server to point to the SQL Server or SQL instance of ...

1)Configure the SQL alias %SqlInstance; on the SharePoint front-end web server to point to the SQL Server or SQL instance of the principal database. Then retry the operation. 
2)Ensure that SQL Client Connectivity components are installed on the SharePoint front-end web server. 
3)You can run "ConfigureSharePoint.exe -ResolveAllSqlAliases" command on the SharePoint front-end web server to identify the SQL aliases that cannot be resolved by DPM.