This error message typically indicates an issue with user authentication when interacting with the eBay API. There are a few common reasons why this error might occur:
Authentication Token Issues
1. Expired Token: The most frequent cause is that your eBay API authentication token has expired[1]. eBay access tokens have a limited lifespan and need to be refreshed periodically.
2. Invalid Token: The token being used may be invalid, either because it was incorrectly generated or has been revoked[1].
Authorization Problems
1. Incorrect Credentials: The client ID, client secret, or other authorization credentials may be incorrect or mismatched[1].
2. Insufficient Permissions: The user account associated with the token may not have the necessary permissions to perform the requested action.
Resolving the Error
To resolve this error, you should:
1. Check Token Validity: Verify if your access token is still valid and not expired.
2. Refresh the Token: If expired, obtain a new access token using the refresh token or re-authenticate.
3. Verify Credentials: Double-check your client ID, client secret, and other authentication details.
4. Review Permissions: Ensure your eBay account has the necessary authorizations for the API calls you're attempting.
If the issue persists after these steps, you may need to contact eBay developer support or AccelerList customer support for further assistance.