The scheduled backups might fail with the error "All operations failed", but if you open the details you will see two backup jobs - one successful and one failed. The backups are actually created.
Agent Status is "Agent is inaccessible"
If an existing scheduled collection gets renamed and then the schedule gets modified, another schedule will get created resulting in two working schedules.
There is a defect when RMAD is deployed on Windows 2008, Windows 2008 R2, Windows Vista or Windows 7. Once the computer collection is renamed the scheduled job is not actually renamed and when you update a computer collection properties the configuration is checked and as no scheduled task with the same name is found one more task is created. It leads to the conflict when several scheduled backup jobs are trying to be launched simultaneously.
Upgrade to Recovery Manager for AD or Recovery Manager for AD Forest Edition 8.2
Go to Windows Scheduled Tasks and delete extra schedules tasks manually.
If this work around is unsuccessful, you may need to create a new collection and move the Domain Controller(s) to the new collection.
Steps to reproduce the issue:
1. Create a collection
2. Set a schedule
3. Rename the collection
4. Change the schedule settings (change the time for example)