Windows Backups Failing with Associated VSS 8193 Error. In the Application Event Log was a prominent VSS error saying something about a ConvertStringSidToSid function which failed.
Here’s the original text for better searchability:
Log Name: Application
Source: VSS
Date: 27.06.2017 21:00:21
Event ID: 8193
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: MYcomputer.anydomain.net
Description:
Volume Shadow Copy Service error: Unexpected error calling routine ConvertStringSidToSid(S-1-5-21-2828234547-00000000000-1509355905-1125.bak). hr = 0x80070539,
The security ID structure is invalid.
Operation:
OnIdentify event
Gathering Writer Data
Context:
Execution Context: Shadow Copy Optimization Writer
Writer Class Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}
Writer Name: Shadow Copy Optimization Writer
Writer Instance ID: {74a61a33-665e-4041-b325-726825b2bf8e}
This was followed by a 521 Event from Windows Backup telling you that the Backup operation failed.
The hint was already in the event details from the VSS error:
ConvertStringSidToSid(S-1-5-21-2828234547-00000000000-1509355905-1125.bak)
Can you spot the SID with the BAK extension at the end?
Looked at the ProfileList a regkey on that machine.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileListAnd here it is:
Followed KB947215 and ultimately removed the Profile with the BAK extension and started another Windows SystemState Backup, which succeeded without any errors.
