A Microsoft file hosting and synchronization service.
The described behavior ("Upload pendente", OneDrive Personal Vault failing with 0x800706d9 and 0x8004de44, only on one PC, persisting after Office/Windows/OneDrive resets) is consistent with a local client-side issue blocking OneDrive/Office from correctly authenticating and uploading files.
From the provided scenario, the confirmed root cause is the coexistence of two resident antivirus products (Kaspersky + Avast) on the same machine. Even when both are “paused”, their network and file-system filter drivers remain active and can interfere with:
- OneDrive sync engine communication
- Office apps’ ability to verify permissions and upload files
- Personal Vault authentication and secure channel establishment
This aligns with known guidance that third‑party security or monitoring components can cause intermittent or silent issues with Office/OneDrive operations and that the fix often requires changing the security/AV configuration, not just restarting apps.
To resolve and prevent similar issues:
- Keep only one resident antivirus solution enabled on the machine (for example, Windows Defender or a single third‑party AV).
- Fully uninstall the additional antivirus product(s) instead of just pausing them, because their drivers and filters remain loaded while installed.
- Restart Windows after uninstalling the extra AV so drivers are unloaded.
- Then sign out and sign back in to OneDrive and the Microsoft 365 apps with the same account that has permission to upload to OneDrive, and try saving again.
If sync or upload issues persist after ensuring only one AV is installed, additional standard OneDrive/Office troubleshooting from the documentation can be applied, such as:
- Verifying that the account used in Office is the same account used to sync OneDrive and has permission to upload.
- Clearing cached credentials and signing in again.
- Unlinking and re‑linking OneDrive.
- Ensuring files are not locked by other applications and that there are no duplicate filenames causing sync conflicts.
References:
- "UPLOAD BLOCKED" error when you save OneDrive-synced files in Microsoft 365 apps
- Fix problems uploading files on the OneDrive website
- What do the OneDrive error codes mean?
- Troubleshoot file upload issues with OneDrive
- Restrictions and limitations in OneDrive and SharePoint
- Antivirus and intermittent issues when you view Office documents by using Office Online Server