OneDrive for Business on macOS: uploads fail silently — failed upload count climbs, zero bytes uploaded, no error surfaced

Damien Cassaigne 0 Reputation points
2026-08-12T08:26:21.0166667+00:00

Environment: OneDrive for Business sync client 26.145.0728.0009 on macOS (Apple Silicon), Files On-Demand on, three business accounts on one machine. Affected account: ~10,700 files / ~1,900 folders, ~10.6 GB used (~1% of quota).

Symptom: one account stopped uploading. Downloads work normally. Over one hour of uptime after a clean restart:

  • numFileFailedUploads climbed 0 -> 57
  • numFileUploads = 0, successfulBytesUploadedTotal = 0
  • FilesToUpload = 5, BytesToUpload = 641286
  • numUploadErrorsReported = 0, failedBytesUploadedTotal = 0
  • syncStallDetected = 0, scanStateStallDetected = 0
  • local changes ARE detected (numLcChangeFile = 21)
  • 200 GB free locally

Failures are counted in one field while zero errors are reported in another, and the client's own stall detectors stay clean. Nothing surfaces in the UI.

Server side: a direct Graph folder listing (not search, which lags) shows one subtree uniformly ~18% short by byte count, stalled ~36 hours. Other subtrees on the same account caught up normally. New files written into the stale subtree never appear.

Possibly related, now cleared: the sync database was rejecting a folder deletion in a loop - DbfsMacboxMftRecordConstraintViolation, "record has at least one non-tombstoned child", SQLITE_CONSTRAINT_TRIGGER on dbfs_mftrecord, retried every 30s, PostponedChanges.cpp / PostponeChange LC_DELETE_FOLDER with DeletionTrigger::LoadedFromDB. The folder had been replaced on disk by a symlink. Removing the symlink stopped that loop. Uploads did not resume.

Questions:

  1. What does a rising numFileFailedUploads with numUploadErrorsReported = 0 indicate, and which log field identifies WHICH files are failing and why?
  2. Is there a supported way to clear a postponed LC_DELETE_FOLDER that is reloaded from the database at every start, short of a full sync-engine reset?
  3. Is there any Microsoft-supported way to collect and submit OneDrive sync logs from macOS? SaRA appears Windows-only and its CLI was deprecated in March 2026; the macOS troubleshooting page gives no log-collection route.

Happy to supply decoded .odl extracts.

Microsoft 365 and Office | OneDrive | For business | MacOS
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  1. Kien 980 Reputation points Independent Advisor
    2026-08-12T09:35:05.8533333+00:00

    Dear @Damien Cassaigne,

    Firstly, please check if other users having similar issue as you and try these basic troubleshooting steps if you have not tried them. Fix OneDrive sync problems on Mac | Microsoft Support

    For further investigate, you can collect fiddler log and please share the internal diagnostic counters referenced in your post with the support engineer. As these counters are not publicly documented. Capture web requests with Fiddler - Power Query | Microsoft Learn

    Based on the diagnostics you shared, the issue appears to be more complex than a typical OneDrive sync problem.

    From your description, OneDrive is still detecting local changes, but those changes are not successfully reaching the service. At the same time, uploads are not progressing and no corresponding error is being surfaced in the client.

    To assist you in details, Microsoft’s support team will need to step in. A technical support engineer can perform a remote session to investigate the situation verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis.   

      Here’s what your Office 365 Global Admin should do next:       

    1. Submit a Service Request: The Global Admin should create a service request with Microsoft support to get advanced technical assistance and diagnostics. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin.     
    2. Find Your Microsoft 365 Admin: If you’re unsure who the Global Admin is within your organization, you can find guidance on locating them here: How do I find my Microsoft 365 admin? - Microsoft Support.    
    3. Call Microsoft Support: For additional assistance, use this link to find the appropriate contact number: Global Customer Service phone numbers - Microsoft Support

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