What I've done was created a new cube inside an existing Analysis Services Multidimensional project and paralleled it with an existing cube. I also changed the target deployment database (test_db_1) to that other than what SharePoint is currently directed towards (prod_db_1) in the reports under Performance Point. The new cubes built and deployed just fine and I see the new cubes in the new database test_db_1 under the current server.
I've then opened PerformancePoint and added the new DB as a new data source. Tested the connection and it passes. Then I try to create a new report, an analytic chart, and that's when I get the error
The Unattended Service Account "domain\user" does not have permissions to see this data. Additional details have been logged for your administrator.
But I'm unable to see these additional details because I lack access.
My administrator has told me it has something to do with the new cubes because the existing cube within the test_db_1 database works. But I see no settings, properties, options for anything that has to do with permissions.
I've been searching all over the web since yesterday trying to understand the reason behind this error.
Under SSMS, ask the administrator to connect to the Analysis services engine. Under "Roles" look at the user there and right click > properties.
In the window go to Cubes on the left hand navigation pane and see if your new cube is listed. If not add it in then that should do the job.