Recently I had an issue running SCCM 2012 SP1 reports from within the Configuration Manager Console. They would run from SQL Reporting Services fine.
The SQL Reporting Services were running from a remote server.
I checked the smsadminui.log a came across the following error:
The issue was a result of Report Viewer not working as expected.
To resolve the issue I removed the Report Viewer and reinstalled.
You can re-run the Report Viewer from the following path:
C:\Program Files\Microsoft Configuration Manager\AdminConsole\bin\ReportViewer.exe