This pop-up error message is reported when attempting to create a SQL Server backup set at the step when the Windows backup set credentials are entered or while running a backup or restore for SQL Server backup set.
a) The Windows account used for the backup set credentials does not have appropriate rights on the backup target computer (cannot connect to the backup target SQL Server instance). At the time the DS-Client starts the backup or restore, it uses the backup set credentials to connect to the target SQL instance and run ( via ODBC ) a query to retrieve information on the database to be processed.
b) the "SQL Server Browser" service is not enabled for the backup/restore target SQL Server instance.
c) The service corresponding to the SQL Server instance attempted to be backed up is not started.
a) Ensure the Windows account used for the backup set credentials is at least member of "Backup Operators" group on the backup target computer and that is able to connect to the backup/restore target SQL Server instance ( use on the DS-Client computer the "Data Sources (ODBC)" utility available in "Administrative Tools" to connect to the target SQL Server instance and confirm if the connection is allowed).
b) Set to 'automatic' and start the SQL Browser service.
c) start the corresponding SQL Server instance service.