Hiya Guys, I'm new here (and new to SSRS) - so hopefully someone will be able to help :-) I've created a Shared Data Source (OLE DB Oracle) which connects and runs my Report correctly within Visual Studio 2008. However, when I attempt to run the Report via Report Manager I receive the error: An error occurred during client rendering. An error has occurred during report processing. Cannot create a connection to data source 'Spider'. ORA-12638: Hentning af ID-oplysninger fejlede (The Server is located in Denmark: ORA-12638 is apparently "Credential Retrieval Failed" - however I know the credentials are correct as the same Data Source works via Visual Studio). Does Report Manager send a data request on another port to Visual Studio? The Oracle database is located on a different server and so perhaps I require another port to be opened?! If anyone can provide any thoughts then I would be very grateful! Cheers, Steve.

*SMUG FACE* As no one seems to know the answer - I'll post my fix here in the off-chance it helps someone in the future :-) After a LOT of research the issue pointed towards the "Double-Hop Authentication" problem - and this article is excellent: http://redmondmag.com/Articles/2010/08/23/Reporting-Services-Double-Hop-Authentication.aspx?Page=1 As it happened - I don't have Domain Admin rights, nor an Active Directory Account for my "Service Account" for SSRS - so instead of trying to explain to our Global IT what I was attempting (and not knowing if it would work) I decided to use my Local Admin Account on the Server as my "Service Account". I was therefore unable to run the steps in the walk-through (above) - except for the last one on Page 2. I updated tag <RSWindowsNTLM/> to <RSWindowsNegotiate/> in file "...Microsoft SQL Server\MSRS10.MSSQLSERVER\Reporting Services\ReportServer\rsreportserver.config", restarted the "SQL Server Reporting" Service, and BOOM!!! The report works. I thank you and good night. Thank you for all your help :-) Steve.