n8n - 💡(How to fix) Fix LinkedIn node fails with 'refreshToken is required' for standard OAuth apps (no Marketing Developer Platform) [1 comments, 2 participants]

Summary

The LinkedIn node crashes with NodeApiError: refreshToken is required (ERR_ASSERTION) when the stored OAuth credential does not contain a refresh token. This affects all standard LinkedIn apps that have not been approved for LinkedIn's Marketing Developer Platform (MDP).

Root Cause

LinkedIn only issues refresh tokens to apps approved for the Marketing Developer Platform. Standard apps using the "Share on LinkedIn" product receive a 60-day access token and no refresh token. This is documented LinkedIn behavior, not a user misconfiguration.

When the access token expires (or n8n attempts to refresh it), the call chain reaches:

client-oauth2-token.js → refresh() → a.ok(this.refreshToken, 'refreshToken is required')

This hard assertion throws an opaque ERR_ASSERTION error instead of a useful message.

Additionally, the LinkedInOAuth2Api credential definition does not include offline_access in its scope — and LinkedIn rejects offline_access for standard apps with invalid_scope_error: Unknown scope "offline_access" — so there is no way to obtain a refresh token through normal OAuth flow without MDP access.

Steps to Reproduce

1. Create a standard LinkedIn app (no Marketing Developer Platform product)
2. Add LinkedIn OAuth2 credential in n8n and connect via OAuth
3. Run a workflow using the LinkedIn node
4. Wait for the 60-day access token to expire (or revoke and reconnect)
5. Run the workflow again → NodeApiError: refreshToken is required

Expected Behavior

When no refresh token is present and the access token is expired, n8n should throw a clear, actionable error:

"LinkedIn access token has expired. Please reconnect the credential."

Or better: attempt the request with the existing access token, and only surface the re-auth message on a 401 response.

Actual Behavior

{
  "errorMessage": "refreshToken is required",
  "errorDetails": {
    "rawErrorMessage": ["refreshToken is required"],
    "httpCode": "ERR_ASSERTION"
  }
}

Stack:

NodeApiError: refreshToken is required
    at ExecuteContext.linkedInApiRequest (nodes/LinkedIn/GenericFunctions.ts:71)
    at @n8n/client-oauth2/src/client-oauth2-token.ts → refresh()

Environment

• n8n version: 2.16.1 (self-hosted)
• Node.js: 22.22.2
• LinkedIn app product: "Share on LinkedIn" (standard, no MDP)

Suggested Fix

In packages/@n8n/client-oauth2/src/client-oauth2-token.ts, replace the hard assertion:

// Before
assert.ok(this.refreshToken, 'refreshToken is required');

// After
if (!this.refreshToken) {
  throw new Error('OAuth token expired and no refresh token is available. Please reconnect the credential.');
}

Additionally, consider documenting in the LinkedIn credential or node description that refresh tokens require LinkedIn Marketing Developer Platform access, and that standard app tokens expire after 60 days.

Workaround

Re-authorize the LinkedIn credential before the 60-day access token expires. The node works correctly with a fresh (non-expired) access token.