We had a simple goal of changing our Backup Exec credentials. You'd think modifying the System Logon Account and Backup Exec services would be enough but for whatever reason our jobs/selection lists retained incorrect credentials.
After several hours of troubleshooting this was solved by trashing all our policies/jobs/selection lists and recreating them.
You can add this to numerous other bugs in 11d that makes me regret upgrading from 10d.