Hi Everybody,
a Customer of mine posted the following in R&D forum because we have some issues with his M365 Backup. They have a Case open since May adressing this issue but there is only litte to none progress. I thought that maybe anybody here might had a similar issue in the past and maby even a solution or workaround:
We’re currently facing a critical issue involving both Veeam Backup for Microsoft 365 and Veeam Backup & Replication (VBR), and we’re hoping to hear from others who may have encountered something similar.
Background: After restoring Office files (Word, Excel, PowerPoint) — whether from Veeam Backup for Microsoft 365 or via VBR from local backups — the files can no longer be opened. They appear to be corrupted, even though they were fully functional in their original state on SharePoint or in the file system. Restoring to different SharePoint sites or local paths didn’t help. One notable detail: the restored files are smaller in size than the originals.
Suspected Cause: We suspect a connection to Microsoft’s Sensitivity Labels (specifically the “Confidential” label). The affected files were labeled accordingly, and our internal documentation states that only pre-authorized users are permitted to open or edit them.
Questions for the Community:
Has anyone experienced similar issues with corrupted files after restoring from Veeam Backup (M365 or VBR)?
Was there any link to Microsoft Sensitivity Labels or Conditional Access policies?
Were you able to resolve the issue through configuration changes or workarounds?
Are you using Microsoft’s “Confidential” sensitivity label in production alongside Veeam Backup — and if so, what has your experience been?
Context: Veeam Support is involved (Case #07706842), but no final resolution has been provided yet. They’ve confirmed that Conditional Access applies at the site level, not the file level — but there still seems to be a conflict in our case.
We’d really appreciate any insights or shared experiences — especially if you’ve successfully integrated Microsoft Sensitivity Labels into your backup and restore strategy.
Link to R&D entry: Corrupted Files After Restore from Veeam Backup for M365 and VBR – Related to Microsoft Sensitivity Labels? - #07706842
Thanks for you help!!
Regards
Chalid