A backup operation fails with this error message:

| error 0x9: The shadow copy provider had an unexpected error while trying to process the specified operation.
| line: 0x2aacb7b2ab852ac
| file: k:\3539\fdisk\ver2\arch\windows\win_errors.cpp:40
| function: Fdisk::AddKstatusError
| code: 0x8004230f
| $module: arx_agent_fork_vsa64_3539

You have a 3rd party backup solution - StorageCraft ShadowProtect - installed on the machine along with Acronis software.