Azure Backup: Unable to undelete recovery services vault backup items — Soft delete and protection status clarification

Hello Austin, thank you for posting your query on Microsoft Q&A platform.

It looks like your PowerShell output already answers the first question: DeleteState = NotDeleted means the item is neither soft-deleted nor in deferred deletion. Azure Backup only sets DeleteState to ToBeDeleted when protection is stopped with delete data (which starts the 14-day soft-delete clock). Since your item never entered that state, Undelete is correctly greyed out, there is nothing to undelete, and no vault/soft-delete change is needed.

The missing daily backups are a separate, client-side cause. For MARS file-and-folder backup, the schedule lives in the MARS console on the server, not in the vault. "Stop protection and retain backup data" halts all future jobs while keeping every existing recovery point which is exactly your fingerprint: last backup 9/3/2026 11:00 AM, LastBackupStatus = Completed, recovery points intact, no failed job to alert on.

Hear you can try:

1. On the protected Windows server, open the MARS console > Actions > Schedule Backup > Modify a backup schedule for your files and folders. Verify: check whether "Stop using this backup schedule but keep the stored backups until a schedule is activated again" is selected, if yes, that's the cause.
2. Select Re-enable backup schedule, set your daily frequency and retention, and finish the wizard. Verify: the MARS Jobs pane shows a newly scheduled job.
3. Run Back Up Now to validate end-to-end. Verify: job completes as Completed, and the vault's Backup items → Azure Backup Agent blade shows an advanced Latest restore point.
4. If a schedule is already active and still nothing runs, check the MARS pre-checks: agent up to date, network connectivity to Azure, Microsoft Azure Recovery Services service Running, 5–10% free space on the scratch/cache volume, antivirus not blocking, and Get-ExecutionPolicy -List. if LocalMachine is restricted, set it to Unrestricted or RemoteSigned from an elevated prompt.

On the error code: BMSUserErrorInvalidAPIVersionMABProtectedItemsList is a service-side error on the list protected items call for MAB (MARS/MABS) workloads. It affects how the portal reads/renders item state — it does not stop your backups. Re-read the item with a current module to confirm:

Install-Module -Name Az.RecoveryServices -Force 


$vault = Get-AzRecoveryServicesVault -ResourceGroupName "<rg>" -Name "<vault>" 

Get-AzRecoveryServicesBackupItem -BackupManagementType MAB -WorkloadType FileFolder -VaultId $vault.ID | Select-Object Name, ProtectionState, ProtectionStatus, DeleteState, LastBackupTime, LastBackupStatus

Two cautions: please don't disable soft delete to "release" the item — it isn't engaged here and disabling it only weakens ransomware protection. And Undo-AzRecoveryServicesBackupItemDeletion won't apply: it acts only on ToBeDeleted items and returns "Undo-deletion is only supported for AzureVMs" for non-VM workloads.

Official documentation

• Manage MARS Agent backups (stop-protection modes and Re-enable backup schedule)
• Soft delete for virtual machines (NotDeleted → ToBeDeleted, 14-day retention)
• Secure by Default with Soft Delete for Azure Backup - Azure Backup | Microsoft Learn (hybrid MARS/DPM/MABS behaviour; free for 14 days, charged beyond)
• Troubleshoot the MARS agent (pre-checks, execution policy, MSOnlineBackup repair)

Please share the screenshot from Step 1 and the PowerShell output above, if the schedule was stopped, Steps 2–3 will restore daily backups today.

Hope this helps, IF you have any question, please do let us know.

Thanks,