I'm having problem with 3rd party backup software relying on VSS (transfer speed rapidly decreasing towards finish). The software is providing own solution for locked volumes, but for some reason it won't ever kick in. therefore always using VSS service which appears working but somehow broken.
From the event log the only critical error during the backup is related to ASR Writer (event id 8193)
Volume shadow copy service error: Unexpected error on routine call IVssAsrWriterBackup::GetAsrMetadata. hr= 0x80070001, Incorrect function.
Operation:Event PrepareForBackup
Also in the list of VSS writers, only ASR has positive last error
Writer name: 'ASR Writer'
Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}
Writer Instance Id: {47366552-4ab8-4b1a-a683-e68a100bfd3b}
State: [5] Waiting for completion
Last error: Non-retryable error
I don't know if it's related to my slowing down issue but may be.
Please for some clues how to fix the thing.
The OS used is Windows 8.1 (x64) / not server