SharePoint Online and OneDrive for Business Backup Jobs Fail with (403) Forbidden Warning Message

Challenge

SharePoint Online or OneDrive for Business backup jobs fail with the following message:

2/5/2020 5:32:43 PM :: Processing site https://site.sharepoint.com/sites/111/subsite finished with warning: Failed to backup item version: /<path>/1024/Shared Documents/<file>, version: 2.0, The remote server returned an error: (403) Forbidden. :: 0:00:21

Cause

Due to limitations of history of file versions, the file cannot be downloaded.

Solution

To confirm that limitations of history of file versions cause the error, do the following:

1. Open the affected OneDrive or Site in the Web-browser.
2. Find the file that cannot be downloaded and open Version history.

3. Left-click on the date.

As a result, the same 403 error must appear, which confirms that the file is inaccessible. Make sure to contact Veeam Technical Support to troubleshoot the issue.