Acronis Backup 11.5 fully supports Hyper-V generation 2 virtual machines starting with Update 6 (build 43909 or 43713 depending on the localization)
This article will help you to troubleshoot issues with backup via Command-line utility in Acronis Backup.
You run a backup using Command-line utility, it fails with an error message.
Backup fails with the following error:
The activity has failed because the machine has been shut down unexpectedly