Avamar: Windows Client Upgrade Fails with Error “Upgrade Verification Failed”

Upgrade of the Avamar Windows client fails with the error:

• Upgrade verification failed. Try to run the installer again.

• The same upgrade succeeds on other clients, indicating the issue affects only one specific system.
• The problem typically occurs after an incomplete or unclean uninstall of a previous Avamar client or plug-in.
• Attempts to uninstall the old client using msiexec /x return:

  The software you are trying to uninstall is not installed.
  

• Debug logs generated using:

  msiexec /i AvamarClient-windows-x86_64-<client-version>.msi /L*v logxxx.txt
  

  show entries similar to:

  VALIDATEUPGRADETABLE_ERROR
  Upgrade verification failed. Please try to run the installer again.
  MSI (s): Product: EMC Avamar for Windows -- Upgrade verification failed.
  

• Registry keys referencing older Avamar components may remain, even if:
  • /avs folder still exists under C:\Program Files (x86)\avs
  • Avamar icon appears in the status bar
  • Backup agent service is running
  • Control Panel shows no Avamar component installed

• The issue occurs because remnants of a previous Avamar client or plug-in remain in the Windows registry after an incomplete uninstall.
• These remnants trigger the Previous Version Validation check during installation, causing the upgrade to fail.
• Root cause is typically environmental, such as:
  • Corrupted Windows OS components
  • Missing Microsoft updates
• This is not an Avamar product defect but an OS-level issue that interferes with uninstall operations.

Permanent Solution

• Work with your System Administrator or Microsoft Support to resolve OS-level issues.
• Investigate registry inconsistencies or missing system updates.
• Fixing the root cause prevents recurrence.
• If Microsoft Support requires collaboration with Dell, create a Service Request for the Avamar Support team.
  • Reference this KB in the request and clearly state what assistance is needed from Avamar Support.

Microsoft Recommended Fix (OS Repair)

• In a past scenario, Microsoft Support identified missing PowerShell module folders under:

  C:\Windows\System32\WindowsPowerShell\v1.0\Modules
  

  • Normally, this path should contain many subfolders, but only a few were present.
• To repair OS inconsistencies, run System File Checker (SFC):

  sfc /scannow
  

  • Run this command in an elevated Windows Command Prompt.
  • Description: /scannow scans all protected OS files and repairs them as necessary.
  • After completion, the missing modules should be restored, and the Avamar client upgrade should succeed.

Workarounds

1. Disable Version Verification

   • Install the client using the SKIPUPGRADEVERIFICATION flag:

     msiexec /i AvamarClient-windows-x86_64-<client-version>.msi /L*v logxxx.txt SKIPUPGRADEVERIFICATION="TRUE"
     

   • This bypasses version checks and completes installation.
   • Note: This does not resolve the underlying OS issue.

2. Rollback and Reinstall

   • Reinstall the previous client and plug-in, then uninstall cleanly before upgrading.
   • Example steps:
     • Uninstall Exchange plug-in and File System client (if present).
     • Reinstall old client and plug-in using msiexec with logging enabled.
     • Uninstall old components using msiexec with logging enabled.
     • Remove or rename the /avs directory manually.
     • Reboot the system.
     • Install the new client and plug-in using msiexec with logging enabled.

3. If Issue Persists

   • Open a Service Request with Dell Support and provide the installation logs for further assistance.