Backup jobs with SharePoint Online or OneDrive for Business items fail with the following errors:
Error: The remote server returned an error: (500) Internal Server Error. Error: The remote server returned an error: (409) Conflict.
- If you are experiencing these errors in versions higher than Veeam Backup for Microsoft Office 2.0, contact Technical Support.
- Different error codes starting from version 3.0 my appear. For more information, see this KB article.
Items being backed-up might be blocked by the internal SharePoint Online antivirus. For more information, see this Microsoft article.
To check whether items are infected, open OneDrive or Site which cannot be backed-up and try to download files manually. If the files you are trying to download are infected, the following error appears.