vRanger Backup: "Error Message: 3208 - can't read disk" when performing physical backup (4045429)

When performing a physical backup in vRanger 6 or higher, backup task fails with the following error:

Error Message: 3208 - can't read disk <physical disk information>

Loss of connectivity to the Physical Backup Agent installed on the source computer

Possible causes:
- reboot or shutdown of computer
- network outage
- Physical Client agent was terminated

Ensure that the the computer is online and pingable from the vRanger computer
Turn off firewall/UAC

Retry the backup job