Facebook Graph OAuth2 connection fails after successful authorization in n8n Cloud

Questions
1

Hello n8n Community,

I am having trouble connecting Facebook Graph API OAuth2 to my n8n Cloud workflow.

Environment

  • n8n Cloud

  • n8n version: 2.35.7

  • Meta app: Everyday Tech Finds

  • Facebook Graph OAuth2 credential

What I did

  1. Configured the Meta app and OAuth redirect URI.

  2. Set custom OAuth scopes: public_profile, pages_show_list, pages_read_engagement, pages_manage_posts.

  3. Completed Facebook authorization and approved the requested Page permissions.

  4. Facebook confirmed that my account was connected to the app.

  5. After redirecting back to n8n, the callback page showed:

Error: [object Object]
Failed to connect. The window can be closed now.

The “More details” section did not show any additional information.

Could someone help me identify why the OAuth callback or token exchange is failing and how to resolve it?

I can share screenshots with sensitive information hidden.

Thank you.

2

Hey @Everyday_Tech_Finds, while you wait for a response, here are some things that might help:

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@rickv - you’ve helped with similar issues before, can you take a look?

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3

Thanks for letting us know about this, We have created IAM-1530 as the internal dev ticket to look into it.

4

Hey @Everyday_Tech_Finds, you can bypass the failing OAuth callback for now. In the Facebook Graph API node, change Authentication to Access Token and save a valid token from Meta’s Graph API Explorer in a Facebook Graph API credential. Use a Page access token if you’re publishing to a Page.

This gets you around the connection flow, but doesn’t fix OAuth itself. The [object Object] message hides the actual error, and IAM-1530 is already tracking it. You’ll need to replace the token if it expires or is revoked.

5

Hi @Everyday_Tech_Finds, could you try connecting once more and add the exact time of that attempt, including your timezone?

Also paste the debug information from Help → About n8n → Copy debug information.

On 2.35.7, n8n logs the callback exception on the server as OAuth2 callback failed. That gives the team investigating IAM-1530 a fresh attempt to check in the Cloud logs and identify the error behind the popup’s [object Object] message.

6

While IAM-1530 is open, two things are worth ruling out, because “[object Object]” usually means the code-for-token exchange returned a Graph error that n8n didn’t print:

  1. App Secret: make sure it’s the App Secret from App Settings → Basic, not the Client Token. That mismatch only fails at the exchange step, after Facebook already says “connected”.
  2. Redirect URI must match exactly (https://oauth.n8n.cloud/oauth2/callback, no trailing slash) under Facebook Login → Valid OAuth Redirect URIs.

If both are already right, the timestamped retry Anshul asked for is the fastest way to get the real error out of the Cloud logs. Meanwhile, Deepankar’s Page access token route will get you posting today. Exchange it for a long-lived token so it doesn’t expire within hours.