PROBLEM:
You upgraded DPM after the upgrade you can click to run any reports in “Reporting” within the DPM console and you get an error like the following:
Cannot open database “DPMDB” requested by the login. The login failed. Login failed for user ‘%servername%\DPMR$%servername%.
CAUSE:
The account ‘%servername%\DPMR$%servername%. doesn’t have the correct mappings for the DPM database, therefore the reporting services cannot access the database to pull out the information to make the reports.
SOLUTION:
Open your DPM 2012 instance using SQL management studio.
Then expand the Security node, then Logins; right-click %servername%\DPMDBReaders$%servername% and select properties.
Select User Mapping on the left hand side; in the upper right pane, under “Users mapped to this login:” verify DPMDB is selected; In lower right pane, ensure db_datareader and public are both selected; click OK.
Now try the report again, it should work.