Backups fail with The requested object was a duplicate. For example:
Replay.Agent.Contracts.Transfer.TransferFailedException: The transfer failed: 'There was a problem with the VSS subsystem on 'AgentX'.' ---> System.AggregateException: One or more errors occurred. ---> Replay.Core.Contracts.Transfer.VssGeneralErrorException: There was a problem with the VSS subsystem on 'AgentX'. ---> Replay.Agent.Contracts.ShadowCopy.ShadowCopyException: Error snapping volumes (C:\;(Volume Labeled 'System Reserved');C:\;D:): The requested object was a duplicate. ---> Replay.Common.Contracts.ReplayException: The requested object was a duplicate.
In this instance, the failures were due to volume C: bring in two separate protection schedules at the same time. This should not be possible:
To verify, go to the Summary page of the agent and look at the Volumes section to see protection schedules.
NOTE: This will trigger a base image fore the volume having an issue.