SharePoint 2010: PerformancePoint Services Dashboard Designer

Error:

The data source no longer exists or you do not have permissions to view it. 
Additional details have been logged for your administrator.

Solutions:

Hi,
Please install the WCF hot Fix for Windows Server 2008 R2 prior to this step.  I believe it should be public soon.
Can you please verify the following see it helps? 
1. Central Administration | Application Management | Manage Service Application | Double click Secure Store Application | Generate New Key
2. Central Administration | Application Management | Manage Service Application | PerformancePoint Service Application | Manage | Update the PerformancePoint Unattended Service Account – First option   
This step needs to be successful, if there is a failure please delete the PerformancePoint Service Application and recreate it.
3. Central Administration | Application Management | Manage Service Application | PerformancePoint Service Application | Administrator | Add the Unattended Service Account and Mark Full Control.
Thank you,
Sundar – MSFT

MSDN