SureBackup job fails with error "Invalid Change Tracker Error Code"

During a VMware SureBackup job processing, a VM may fail to boot with the following error: An error occurred while taking a snapshot: Invalid Change Tracker Error Code.

In Task & Events of the vSphere Client, you can see the following error message: An error occurred while taking a snapshot: Invalid Change Tracker Error Code; Nested Hardware-Assisted Virtualization should be enabled when enabling VBS (Virtualization-Based Security).

To make sure the issue exists, check the job and/or task log files:

1. Navigate to the following location on the Veeam Backup Server: %programdata%\Veeam\Backup.
2. Open the folder that matches the name of the job with an issue.
3. Within this folder, check the following log files:
   • If the VM was started from a linked job, find the task log for the specific VM — %programdata%\Veeam\Backup\<BackupJobName>\Task.<VMName>.<GUID>.log.
   • If the VM was started from the application group, find the job log file — %programdata%\Veeam\Backup\<BackupJobName>\Job.<SureBackupJobName>.log.
4. Search for the following line with error: Error Nested Hardware-Assisted Virtualization should be enabled when enabling VBS (Virtualization-Based Security).

Nested Hardware-Assisted Virtualization was not enabled together with VBS (Virtualization-Based Security).

Add a registry key with the following values on the Veeam Backup Server:
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication\SureBackup
Type: DWORD
Name: UseVhvEnable
Value: 0

For more information see: https://blogs.vmware.com/vsphere/2018/05/introducing-support-virtualization-based-security-credential-guard-vsphere-6-7.html