Below are some notes that I have made, for the configuration of PerformancePoint. These are notes when I have come across problems, for example when I couldn't connect to a data source in the designer, or couldn't even get in the designer without error.
1. Check the PerformancePoint service has been started
2. Check a suitable Unattended Service account has been applied
If using a unique unattended service account for performancepoint (e.g. not the farmadmin or similar), you will need to open SQL Management Studio and connect to Analysis Services. From here you will need to add the performancepoint account to the ProjectServerViewOLAPData role. this error sometimes throws ACL related messages!
3. Check the Secure Store has been setup properly
4. Maybe try checking the Unattended Service Account has DB Owner rights on the relevant Content DB
5. You could also check that Excel Services can connect, as this may generate more helpful error messages or logs