Output of restic version

restic 0.17.3 compiled with go1.23.4 on windows/amd64

What backend/service did you use to store the repository?

rest api

Problem description / Steps to reproduce

1. Start a rest-server using the official repository(actually using a local backend should reproduce this issue).
2. run restic.exe backup in Windows with --use-fs-snapshot flag.

restic.exe -r [repository] backup --use-fs-snapshot [paths to backup]

3. Look at the event log viewer(press Win+R then type eventvwr) then navigate to Windows Logs -> Application.
4. There should be event logs like this.

Volume Shadow Copy Service error: Unexpected error querying for the
IVssWriterCallback interface. hr = 0x80070005, Access is denied.
. This is often caused by incorrect security settings in either the writer or requestor process.

Operation:
Gathering Writer Data

Context:
Writer Class Id: {e8132975-6f93-4464-a53e-1050253ae220}
Writer Name: System Writer
Writer Instance ID: {325f1613-7240-49af-865e-82927f406f7a}

Expected behavior

Such event logs should not be generated.

Actual behavior

Event error log with event id 8194 occurs several times when running the backup with VSS in Windows.

Do you have any idea what may have caused this?

As described in vssclient sample initializing the COM security is required to allow VSS writers to communicate with VSS service.

Did restic help you today? Did it make you happy in any way?

Yes.