OneDrive Business 403

Hi all

I have been running Duplicati backups to OneDrive Business for months - until today when I suddenly got this message:

Forbidden: Forbidden error from request Method: GET,
RequestUri: ‘’, Version: 1.1, Content: , Headers: { User-Agent: Duplicati/ Authorization: Bearer ABC…XYZ }
StatusCode: 403, ReasonPhrase: ‘Forbidden’, Version: 1.1,
Content: System.Net.Http.StreamContent,
Headers: { Cache-Control: private request-id: d7e83c11-8f4b-4fab-8285-xxxxxx
client-request-id: d7e83c11-8f4b-4fab-8285-xxxxxx
x-ms-ags-diagnostic: {“ServerInfo”:{“DataCenter”:“North Europe”,“Slice”:“SliceC”,“Ring”:“3”,“ScaleUnit”:“000”,“RoleInstance”:“AGSFE_IN_9”}}
Strict-Transport-Security: max-age=31536000 Date: Tue, 01 Dec 2020 05:28:52 GMT
Content-Type: application/json Content-Length: 279 } { “error”: { “code”: “accessDenied”, “message”: “Access denied”, “innerError”: { “date”: “2020-12-01T05:28:52”, “request-id”: “d7e83c11-8f4b-4fab-8285-xxxxxx”, “client-request-id”: “d7e83c11-8f4b-4fab-8285-xxxxxx” } } }

Nothing changed. I can still use my OneDrive as usual (read, write files), except for Duplicati.
“Test connection” is still successful
Backing up fails with the message above
Verify a backup fails with “a task was cancelled”
I have multiple backup jobs configured. All of them have the same issue.

Any idea how to debug this issue?

So, here’s the “solution”: It works again and I don’t know why.
Only three things could have had an impact in the meantime: OneDrive changed something, the Duplicati restart helped or it was my Plex server who had eaten up almost all my memory and therefore caused some side effect. Or it was just one of the random hiccups Duplicati has every few months :slight_smile: