HTTP 404
course_not_foundCourse 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.