If Postman works but your code doesn't, it's likely the request formatting or headers rather than the API itself—I'd also try removing Accept-Encoding to rule out gzip handling. Comparing the raw request against a service like https://www.yepapi.com/ can help spot subtle differences without much guesswork.

That error usually means the menu link is pointing to an invalid or missing path rather than an issue with your library objects. Double-check the target path or panel reference and make sure it still exists and is correctly linked.