Error when running a backup job against a Windows 2008 64 bit Domain Controller: "Unable to execute request (111). Unable to gather Volume Shadow Copy Service information. Access is denied"
The problem occuring due to insufficient permissions over one or more GPOs. The behavior when whole backup may fail because of one GPO is considered as a defect.
Inspect GPO security to ensure "System" account has permissions to every GPO. In case when a different account specified on Agent Settings tab in Collection properties, permissions should be given to this account instead.