Microsoft Azure Backup device backups failing with Error Code 0x1FBD1

Question

I have multiple servers running Windows Server 2019 Standard that have suddenly started to have failed scheduled backup jobs with Microsoft Azure Backup. The failed jobs occur for both system state and file/folder backups and they seem to be intermittent. Typically jobs are scheduled for 2100 and the initial job will then fail after some time and data transfer with the attached error code. Azure Backup will then retry the backup job some time later and the backup job will complete without issue and subsequent scheduled jobs will complete for multiple days without issue. The MARS agent running on the devices has been updated to version 2.0.9273.0 and the devices have been restarted. Please can you advise how to resolve these failed jobs as I cannot seem to find any support articles on the topic.

Answer 1

Intermittent failures in Azure Backup jobs can often be caused by network instability, resource contention, or temporary connectivity issues with the Azure service. Since the backups succeed on retry, it's worth checking the event logs (Event Viewer > Applications and Services Logs > Microsoft Azure Recovery Services) for network-related errors. Also, ensure that backup schedules do not overlap, as concurrent jobs can cause failures. If using a proxy or firewall, confirm that the necessary Azure Backup URLs and ports are allowed. Additionally, verifying system performance during backup times and reviewing the MARS agent logs (C:\Program Files\Microsoft Azure Recovery Services Agent\Temp) may help identify the root cause.