- You are backing up a Hyper-V virtual machine in agentless mode,
- Backup fails with the following error:
Unexpected call result. Error code 32768
The most frequent root cause are VSS issues in the guest operating system.
If there is an SQL Server installed on the virtual machine:
Repair the SQL instance on the guest VM:
- Go to Control panel -> Programs and features
- Find the SQL server in the list, select it and click Uninstall/Change:
- Click Repair in the window that appears:
- After repair install completes, retry the backup.
If the issue is not resolved, troubleshoot snapshot issues on Hyper-V as described in Troubleshooting Hyper-V snapshot issues
If there is no SQL server on the virtual machine:
Troubleshoot VSS-related issues on the guest OS as described in KB 36200: VSS Troubleshooting Guide