NVP‑vProxy: File‑Level Restore Fails With "The Guest Operations Agent Could Not Be Contacted"

The NetWorker VMware Protection (NVP) integration uses a vProxy appliance to perform VM backups and restores. A file-level restore (FLR) of a virtual machine fails during the credential validation and mount phase. The vProxy cannot contact the guest operations agent on the target VM. The NetWorker Management Console (NMC) mount results output and the FLR restore log show repeated VIX API errors followed by a connection failure: 

1593xx:nsrvproxy_flr: vProxy Log: YYYY/MM/DD HH:MM:SS TRACE:  [85] Validating credentials with AuthManager ...
1593xx:nsrvproxy_flr: vProxy Log: YYYY/MM/DD HH:MM:SS WARN:   [85] AuthManager.ValidateCredentials: VIX API error (will retry): ServerFaultCode: The guest operations agent could not be contacted.
1593xx:nsrvproxy_flr: vProxy Log: YYYY/MM/DD HH:MM:SS WARN:   [85] AuthManager.ValidateCredentials: VIX API error (will retry): ServerFaultCode: The guest operations agent could not be contacted.
1593xx:nsrvproxy_flr: vProxy Log: YYYY/MM/DD HH:MM:SS WARN:   [85] AuthManager.ValidateCredentials: VIX API error (will retry): ServerFaultCode: The guest operations agent could not be contacted.
1593xx:nsrvproxy_flr: vProxy Log: YYYY/MM/DD HH:MM:SS INFO:   [85] Disconnected from session on vCenter '[MY_VCENTER_NAME]'.
1593xx:nsrvproxy_flr: vProxy Log: YYYY/MM/DD HH:MM:SS ERROR:  [85] Cannot access VM '[MY_VM_NAME]' (vm-3432): ServerFaultCode: The guest operations agent could not be contacted.

The vProxy attempts credential validation three times (will retry), then disconnects from the vCenter session and reports Cannot access VM — confirming the guest operations agent is unreachable. 

The FLR fails to mount the file systems on the target VM. This issue can affect virtual machines running any guest operating system (Linux or Windows) and applies to all NetWorker and vProxy versions.

The target virtual machine does not have VMware Tools installed, or VMware Tools is not functioning correctly. The vProxy FLR process requires VMware Tools to communicate with the guest operating system through the VMware VIX API. Without a functioning VMware Tools installation, the vProxy cannot validate credentials against the guest AuthManager, cannot access the guest operating system, and cannot mount the file systems for file-level restore.

The Dell NetWorker VMware Integration Guide documents this requirement in the "File-level restore limitations" section:

You must install VMware Tools to use file-level restore. For best results, ensure that all virtual machines run the latest available version of VMware Tools. Older versions are known to cause failures when you perform browse actions during the file-level restore operation.

This error occurs when any of the following conditions exist on the target VM:

• VMware Tools is not installed — The guest operations agent does not exist on the VM.
• VMware Tools is installed but not running — The VMware Tools service has stopped or failed to start on the guest OS.
• VMware Tools is running an outdated version — Older versions may not support the guest operations required by the vProxy FLR process, leading to browse or mount failures.

1. Verify VMware Tools status on the target VM:
   • Open the vSphere Client and navigate to the target VM.
   • Check the VMware Tools status in the VM summary. Evaluate the result:
     • Not installed — Proceed to Step 2 to install VMware Tools.
     • Not running — Start the VMware Tools service on the guest OS, then proceed to Step 3 to retry the FLR.
     • Out of date — Proceed to Step 2 to update VMware Tools to the latest version.
     • Running (Current) — VMware Tools is functioning correctly. If the FLR still fails, contact Dell Support (Step 4).
2. Install or update VMware Tools:
   • Install or update to the latest available version of VMware Tools on the target virtual machine. Follow the VMware documentation for the specific guest operating system running on the target VM.
   • After installation or update, verify that VMware Tools shows as Running (Current) in the vSphere Client VM summary.
3. Retry the file-level restore:
   • Re-initiate the FLR operation from the NetWorker Management Console for the target VM.
   • Confirm the FLR completes successfully.
4. Escalate if needed:
   • If the FLR continues to fail after installing the latest VMware Tools and confirming the tools are running, contact Dell Support for further investigation and reference this KB article.