An unexpected network error occurred. (\\HyperV_hostname\path_to_vhd_file)
Application Message ID: 59
Product: DS-Client Category: System Software Version: 13.0 and newer Last Updated: 2018-01-18
Symptoms
The error is reported during backup ( VSS-Aware for Microsoft Hyper-V backup sets).
Cause
The disk holding the vhd file has bad sectors. When running a backup with a file system set with the VSS option enabled (can be statistical with "calculate transmit amount" switch enabled) that protects the same volume, the same error will be reported in DS-User event log, but in the same time an error or warning will be logged in the operating system event viewer / system log signaling a disk issue.
Workaround
check the disk for bad sectors