Error When Connecting Microsoft Outlook OAuth2 API

Questions
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1

Describe the problem/error/question

I’m getting an error when I try to RECONNECT my Outlook credential.

What is the error message (if any)?

Error: Client authentication failed (e.g., unknown client, no client authentication included, or unsupported authentication method).

More details 
{"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: https://aka.ms/NewClientSecret, or consider using certificate credentials for added security: https://aka.ms/certCreds. Trace ID: bbd05175-55f6-450c-bcb5-86f659e9d000 Correlation ID: db985ab3-375a-4c71-af18-977c83083c22 Timestamp: 2025-12-01 02:34:16Z","error_codes":[7000222],"timestamp":"2025-12-01 02:34:16Z","trace_id":"bbd05175-55f6-450c-bcb5-86f659e9d000","correlation_id":"db985ab3-375a-4c71-af18-977c83083c22","error_uri":"https://login.microsoftonline.com/error?code=7000222"}

Failed to connect. The window can be closed now.

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Information on your n8n setup

  • n8n version: 1.121.3
  • Database (default: SQLite):
  • n8n EXECUTIONS_PROCESS setting (default: own, main):
  • Running n8n via (Docker, npm, n8n cloud, desktop app): n8n cloud
  • Operating system: windows
3 Likes
2

Having the exact same issue, looks like the n8n cloud team need to rotate the keys in azure. Please resolve ASAP as we use this for emailing clients!

3 Likes
3

It seems that creating a new credential was the only option last time this happened: Issue with MS Oauth2 on n8n cloud (scroll to the bottom)

4

Also getting this error (two years after the original). I have a lot more accounts to re-auth if that is the only fix, that will be a pain.

5

Found another thread with a response for support. Yes, we need to add new credentials again: Error When Connecting Microsoft Outlook OAuth2 API

7

Update: I was able to resolve the issue. The fix involved creating a new Microsoft Outlook credential, then going through all workflows using the Outlook credential, re-saving them, and selecting the new credential. After this, everything started working as expected.