VMWARE Backup failing with error- VMWARE_GOVMOMI7 | 'VssSyncStart' operation failed: IDispatch error #8449 (0x80042301)
Problem description
VMware virtual machine backups fail with the error VMWARE_GOVMOMI7 accompanied by 'VssSyncStart' operation failed: IDispatch error #8449 (0x80042301).
Scenario / Reproduction:
Taking a standard (non-quiesced) snapshot of the Windows VM succeeds.
Triggering a quiesced snapshot—either via a Druva backup job or manually from vCenter—consistently fails, even though the VMware Snapshot Provider and Volume Shadow Copy services appear to be running inside the guest OS.
Cause
The error code 0x80042301 (IDispatch error #8449) indicates that the Volume Shadow Copy Service (VSS) inside the Windows guest operating system failed to complete the freeze operation required to create an application-consistent (quiesced) snapshot.
When VMware Tools triggers a quiesced snapshot, it invokes Windows VSS writers to prepare applications for backup. If any writer is in a failed state or times out during the freeze event, the snapshot aborts. Common writers associated with this failure include:
SQL Server Writer: Fails if SQL Server cannot reach a consistent state or encounters VDI issues.
Registry Writer: Fails with non-retryable errors during the freeze event.
WMI Writer: Frequently causes quiescing timeouts.
Traceback
Druva EnterpriseWorkloads Log (EnterpriseWorkloadsFL.116037.1781791077.log):
level=error ts=2026-06-18T13:58:09.885371638Z filename=virtual_machine.go:311 method=createVMSnapshot message="VM snapshot creation failed." Error="An error occurred while quiescing the virtual machine. See the virtual machine's event log for details."
vCenter Manual Quiesced Snapshot Error:
Error: 'VssSyncStart' operation failed: IDispatch error #8449 (0x80042301)
Resolution
Step 1: Identify the failing VSS writer
Log in to the affected Windows guest VM and open Command Prompt as an Administrator.
Run the following command:
vssadmin list writers
Review the output for any writer where State is not
[1] Stableor where Last error is notNo error.
Step 2: Inspect Windows Event Viewer and VMware logs
Open Event Viewer on the Windows VM and check both the Application and System logs around the timestamp of the failed backup.
Look for error events from sources such as
VSS,SQLVDI, orSQLWRITER(for example, error0x800423f4- Non-retryable error).(Optional) Inspect the
vmware.logfile located in the VM's directory on the datastore forVssSyncStart failedorCVmSnapshotRequestorentries to pinpoint the exact writer that aborted the quiescing process.
Step 3: Restart VSS and application services
Open
services.mscinside the Windows guest VM.Restart the Volume Shadow Copy service and the VMware Tools service.
If a specific application writer (such as SQL Server VSS Writer) was flagged in Step 1, restart that corresponding service as well.
Step 4: Apply writer-specific remediation
SQL Server Writer failure: Verify SQL Virtual Device Interface (VDI) permissions/settings and confirm all databases are online and healthy.
OS-level VSS writer failure (Registry / WMI Writer): Reboot the Windows VM if restarting services does not restore the writers to a
[1] Stablestate. If the writers continue to fail after a reboot, engage Microsoft Support to repair the Windows VSS framework.
Verification
Run
vssadmin list writersin an elevated Command Prompt on the Windows VM and confirm all writers reportState: [1] StableandLast error: No error.In vCenter, right-click the VM and select Snapshots > Take Snapshot, ensuring Quiesce guest file system is checked, to verify the snapshot completes without errors.
Trigger an on-demand backup job from the Druva Management Console and confirm it completes successfully.