In our internal environment randomly the Monitoring and CDR Reports randomly stopped working. After some troubleshooting and help from Google translator: http://blogs.technet.com/stefan/archive/2009/07/07/probl-me-de-visualisation-des-rapports-cdr-qoe.aspx
We were able to verify that the RTCReportPack account did not have “Allow Log on Locally” on the SQL Server.
After clicking to generate a report we would see this error:
After adding the RTCReportPack account to the Allow Logon Locally group in the local security policy this went away.