HTTP 404
course_not_found

Course not found

No active course matches the supplied Udemy course ID or slug.

Resolution

Check the identifier or search the course catalog first.

Response handling

Keep the response's request_id for diagnostics. Retry only transient rate limits and 503 responses, respecting Retry-After with bounded exponential backoff and jitter. For monthly_quota_exceeded, stop polling until RateLimit-Reset or upgrade. Correct 400, 401, 403, and 406 requests before retrying.