VERIFIED SOLUTION i
While refreshing the Portrait system database after the database upgrade, the system data refresh throws following error.
[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied while performing system data refresh in SQL Server
This could be caused due to incorrect server name/instance in the 'RefreshSystemData' executable. Server name/instance information is passed with '-S' flag during 'RefreshSystemData' execution.
ResolutionUPDATED: April 21, 2017
Ensure correct Sever name/instance is passed with '-S' flag is correct and up.