N8n - Microsoft Outlook Authentication issue

Unable to add or edit Microsoft Outlook credentials in n8n

Describe the problem/error/question

When editing or adding a new Microsoft Outlook credential, we are running into the following error message: Error: Client authentication failed (e.g., unknown client, no client authentication included, or unsupported authentication method).

{“error”:“invalid_client”,“error_description”:“AADSTS7000222: The provided client secret keys for app ‘aad843ca-42a7-4219-a3f9-91bcf621d795’ are expired. Visit the Azure portal to create new keys for your app: How to register an app in Microsoft Entra ID - Microsoft identity platform | Microsoft Learn, or consider using certificate credentials for added security: Microsoft identity platform certificate credentials - Microsoft identity platform | Microsoft Learn. Trace ID: 7bb0612b-594b-4ba0-9b52-d47dc9272505 Correlation ID: 0e274e65-2bbc-4f58-b018-93042aa4a507 Timestamp: 2025-12-01 20:14:35Z”,“error_codes”:[7000222],“timestamp”:“2025-12-01 20:14:35Z”,“trace_id”:“7bb0612b-594b-4ba0-9b52-d47dc9272505”,“correlation_id”:“0e274e65-2bbc-4f58-b018-93042aa4a507”,“error_uri”:“https://login.microsoftonline.com/error?code=7000222”}

We support multiple Microsoft Outlook mailboxes across different domains. The issue appears to have started on 1 December 2025 for reasons that are not yet clear. Initial research suggests that creating a new client secret in the Azure Portal may resolve it. However, n8n does not seem to provide a way to update the client secret credentials. In addition, all client domains are returning the same app ID, which doesn’t seem correct. Has anyone else run into this problem?

Information on your n8n setup

  • n8n version: Version 1.107.4
  • **Database (default: SQLite): n8n Cloud
  • n8n EXECUTIONS_PROCESS setting (default: own, main): default
  • Running n8n via (Docker, npm, n8n cloud, desktop app): cloud
  • Operating system: cloud

same for me

I am in the same boat, seems to have just happened

You are not along. Two other forum posts have spun up today with this issue. Also there is a forum post from 2 years ago. Only remedy to get you working ASAP is to recreate credentials, and then in all integrations that use credentials switch to the new. Futhermore, this looks to be an issue that happened exact same day 2 years ago. Feels like n8n has something wrong with certificates and Microsoft OAuth2 handshake. It looks like they can fix on the back end and then restart your instance but you may get yourself working faster by recreating.

Two Additional forum posts from today:
Error When Connecting Microsoft Outlook OAuth2 API - Questions - n8n Community
Microsoft Outlook Client authentication failed - Questions - n8n Community

Forum Post from Two Years ago:
Issue with MS Oauth2 on n8n cloud - Questions - n8n Community

Please see Microsoft Outlook Client authentication failed - #11 by Jon for more info