probably best to do a full verify of items on that particular date range, o close to the minute as you can.
It could just be a corrupt file or it could be something more serious such as anti virus deleting files etc

Have also seen this in environmens where the fingerprint transaction log grows to 100% and can't grow anymore and it causes lots of issues with false positive fingerprints being created

Hi JW,

Definitely no AV on the storage device which is a remote CIFS share. 

SQL Transaction logs may well have filled at various points in the past. 

Could you advise specific EVSVR repair option to resolve?

Can of course ignore them...

So what I would do is the following

1. Log on to the EV server
2. Open a command prompt and CD to your EV installation directory
3. Type EVSVR and press enter
4. Type Edit and press enter
5. Uncheck "Process All Vault Store Groups"
6. Uncheck "Process All Vault Stores"
7. Uncheck "Process All Vault Store Partitions"
8. Uncheck "Process All Archives"
9. In the archive box, choose the Mailbox that was reported in the event
10. Narrow down the users vault store group, vault store and the active partition
11. Set the Date Range to be as close to those events as possible
12. Change Operation to be Verify
13. Change Option to be Complete
14. Save the EVSR and then run it from the evsvr console

Yes, I've already run Verify option. Question is which Repair option will address this event? If Any?

NB Verify does report various "unable to complete retrieval request" events on Savesets within the date range.

OK so you know repair is going to remove them right?
but the option you want is Repair -> DeleteSurplusReferences.

However what i am unsure of is if it will delete an item where the DVS exists but the DVSSP is missing.
I think it will only do a delete from the database when the DVS/DVSCC/DVSPP are all missing together.
What you may end up just having to do is use the blacklist SISPart repair option