error 500 when trying to access a folder with a shared_link using Dropbox API

Hello,

I am trying to get the contents of a folder using a shared link like this:

{"path": "", "shared_link": {"url": "https://www.dropbox.com/sh/xxxxx"}}

I have tried both direct HTTP using postman and also using the Dropbox Javascript API, with exactly the same results - both times I get an HTTP 500 response but no error detail

if I use a folder path like this it works fine:

{"path": "/SomeFolder "}

I have tried different shared links, different folders, different access tokens, even different user accounts but every time the same result