Avamar: Hyper-v Backups Fail with 'failed to Get the Vms for Browse' Due to Missing GUID

Hyper-V cluster backup failing with the following errors:

avhypervvss Error <43381>: Unable to get the VMs for backup.
avhypervvss Error <41732>: Failed to collect the list of remote VMs
avhypervvss Error <41581>: Failed to backup targets. Unable to expand targets.
avhypervvss Error <41662>: Failed to validate and expand the targets.
avhypervvss Error <41659>: Backup did not complete successfully

• It may also fail to browse the Hyper-V virtual machines (VM) using either the Avamar Administrator console or web-based Avamar User Interface (AUI).
• From the avhyperv_plugin_browse.log (located in the shared var folder):

avhypervvss Error <43509>: Failed to get the VMs for browse.
avhypervvss Error <17179>: Failed to get the virtual machines from the Avamar Windows Cluster service: Err=80004005
avhypervvss Error <17182>: Failed to get the VMs from the service
avhypervvss Error <13924>: Unable to get Hyper-V browse items
avhypervvss Error <6677>: Error processing CTL message "<browse_contents pid="Hyper-V VSS" type="backup_destination" ack="false" msgver="3" page_complete="true" pidnum="3032" browsetimeout="10" maxelems="1" incomplete="1" path="" sync="fg" cid="XXXXXXXXXXXXXX" last_ctl_man_key="2-XXXXXXXXXXXXXXXXXXXXX" mid="2720/10996/32" inprogress="false" mcs_version="19.9.0-78" wid="Browse" supports-filters="false">

• The winclustersvc.log file may display the following messages below in DEBUG logging enabled. Debug logging for the DELL Plugin Service for Windows (winclustersvc) process is enabled by creating the winclustersvc.log file in the C:\Program Files\avs\var folder of the active owner. The Failover Cluster Manager tool displays the active Hyper-V node for the DELL Backup Agent service.

2024-02-29 14:20:09 winclustersvc DEBUG<0000>: VmName: SCVMM Preparation - WIN2022 Resources 
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: VmGuidName:  
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: OwnerNodeName: DELLSVR100 
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: resourceName: SCVMM Preparation - WIN2022 Configuration 
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: CsvResourceName: SCVMM Preparation - WIN2022 Configuration 
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: Parsing the VmVersion 0 for Vm SCVMM Preparation - WIN2022 Resources 
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: VMVersion: < 8.0 
2024-02-29 14:20:09 winclustersvc DEBUG<0000>: ExternalDataRoot:  
2024-02-29 14:20:09 winclustersvc ERROR<0000>: Exception in GetVMsForBrowse Index was outside the bounds of the array.

• An alternate error message:

2024-10-09 19:01:49 winclustersvc DEBUG<0000>: CsvResourceName: SCVMM TESTVM Configuration 
2024-10-09 19:01:49 winclustersvc DEBUG<0000>: Parsing the VmVersion 0 for Vm SCVMM TESTVM Resources 
2024-10-09 19:01:49 winclustersvc DEBUG<0000>: VMVersion: < 8.0 
2024-10-09 19:01:49 winclustersvc DEBUG<0000>: ExternalDataRoot:  
2024-10-09 19:01:49 winclustersvc ERROR<0000>: Exception in GetTargetVMsForRCT Index was outside the bounds of the array.

Steps: 

Enable debug logging and reproduce the backup failure to collect detailed diagnostic information. Debug logging can be enabled by selecting Enable debugging messages in the dataset configuration. Alternatively, edit the avhypervvss.cmd file in the shared/var directory and add the --debug flag.

After reproducing the issue, review the winclustersvcl.log file on the active cluster node. Search for the messages Exception in GetVMsForBrowse or Exception in GetTargetVMsForRCT. The name of the problematic virtual machine appears immediately before the corresponding error entry. Refer to the examples in the Symptoms section for guidance.

Remove the problematic VM from Failover Cluster Manager, then retry both the browse and backup operations. If both operations complete successfully, readd the VM to the Failover Cluster Manager.

After readding the VM, confirm that it has a valid GUID assigned. Open an elevated PowerShell prompt on any cluster node and run the following command:

Invoke-Command -ComputerName(Get-ClusterNode).Name -ScriptBlock { (Get-VM | ft computername,vmname,vmid) }

Verify that the VMID field is populated.

Once confirmed, retry the Hyper‑V VM browse operation from Avamar Administrator or the AUI. Run a new backup and confirm that the newly added VM is included successfully.

The following URL provides detailed steps for adding Hyper-V VMs to the Failover Cluster Manager tool: Hyper V: Add a VM as a Cluster Resource (External Link)